Meditation and the Neuroscience of Consciousness: an Introduction

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CHAPTER 19 Meditation and the Neuroscience of Consciousness: An Introduction

Antoine Lutz, John D. Dunne, and Richard J. Davidson

Abstract on the brain and body of long-term practitioners. After an overview of the mecha- The overall goal of this chapter is to explore nisms of mind-body interaction, this section the initial findings of neuroscientific research addresses the use of first-person expertise, on meditation; in doing so, the chapter especially in relation to the potential for also suggests potential avenues of further research on the neural counterpart of sub- inquiry. It has three sections that, although jective experience. In general terms, the sec- integral to the chapter as a whole, may tion thus points to the possible contributions also be read independently. The first sec- of research on meditation to the neuro- tion, “Defining Meditation,” notes the need science of consciousness. The final section, for a more precise understanding of med- “Neuroelectric and Neuroimaging Correla- itation as a scientific explanandum. Argu- tes of Meditation,” reviews the most relevant ing for the importance of distinguishing the neuroelectric and neuroimaging findings of particularities of various traditions, the sec- research conducted to date, including some tion presents the theory of meditation from preliminary correlates of the previously dis- the paradigmatic perspective of Buddhism, cussed Buddhist practices. and it discusses the difficulties encountered when working with such theories. The section includes an overview of three prac- Introduction tices that have been the subject of research, and it ends with a strategy for developing This chapter discusses possible contributions a questionnaire to define more precisely a of meditation to the neurobiological study of practice under examination. The second sec- consciousness and to cognitive and affective tion, “The Intersection of Neuroscience and neurosciences in general. Empirical research Meditation,” explores some scientific moti- on meditation started in the 1950s, and as vations for the neuroscientific examination much as 1,000 publications on meditation of meditation in terms of its potential impact already exist.1 Despite such a high number 497 P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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of scientific reports and inspiring theoretical wide range of practices. Thus, in a typical proposals (Austin, 1998; Shapiro & Walsh, discussion of this kind, West (1987) argues 1984; Varela, Thompson, & Rosch, 1991; that practices as diverse as the ritual dances Wallace, 2003; West, 1987), one still needs of some African tribes, the spiritual exer- to admit that little is known about the neu- cises of the desert fathers, and the tantric rophysiological processes involved in med- practices of a Tibetan adept are all forms itation and about its possible long-term of meditation. Historically, this attempt to impact on the brain. The lack of statisti- categorize diverse practices under the same cal evidence, control populations and rigor rubric reflects some intellectual trends in the of many of the early studies; the hetero- early 20th century, most especially “perenni- geneity of the studied meditative states; alism,” that argue unequivocally for a cer- and the difficulty in controlling the degree tain genre of mystical experience as the of expertise of practitioners can in part essence of religion (Proudfoot, 1985; Sharf, account for the limited contributions made 1998). From the standpoint of the neuro- by neuroscience-oriented research on medi- sciences, the problem with such a position tation. Thus, instead of providing a complete is that it begins from a set of hypotheses review of this empirical literature (Austin, that are difficult to test because they assume 1998; Cahn & Polich, 2006; Delmonte, 1984, that the common element in mystical expe- 1985; Fenwick, 1987; Holmes, 1984; Pagano rience necessarily transcends thought, lan- & Warrenburg, 1983) we choose to address guage, reason, and ordinary perception – our central question from three directions. most of which are required for any reli- The purpose of this first section is to clar- able neuroscientific procedure to test the ify conceptually what the term “meditation” hypotheses. means and to propose an operational def- In addition to the problem of unverifiable inition. We focus on Buddhist meditative hypotheses, the generic use of meditation practices as a canonical example. We pro- as applying to such a wide range of diverse vide a short presentation of the main tenets practices inevitably trivializes the practices of Buddhist psychology and epistemology, as themselves. For example, the unique tech- well as a description of the standard techniques and context of Sufi zikr must be niques used in many Buddhist practices. ignored if they are to be considered the From these standard claims, we then derive same as the Taoist practice of T’ai Chi. In the possible contributions of meditation to short, to make zikr and T’ai Chi describ- neurosciences and develop tentative propos- able with the same term, one must ignore als for a neuroscientific understanding of a good deal of what makes them radically the cognitive and affective processes that different from each other. This would be are altered by training in meditation. In the akin to the use of the word “sport” to refer last section, we review existing neuroelectric to all sports as if they were essentially the and neuroimaging findings on meditation, as same. A typical result of such an approach well as some preliminary correlates of these is the extremely general model proposed by Buddhist practices. Fischer (1971) in which all forms of meditation – exemplified by Zazen and some unspecified “Yoga” practice – fall along the 1. Defining Meditation same trophotropic scale of hypoaraousal, even though attention to the details of Although widely used, the term “medita- many Buddhist practices, including Zazen tion” is often employed in a highly impre- (Austin, 1998), makes a description in terms cise sense such that its descriptive power is of hypoarousal extremely problematic. greatly decreased. One underlying reason for An alternative approach to research on the term’s inadequacy is that, in its typical meditation is to attend more closely to the usage, it refers generically to an extremely particularity of the individual practices in P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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question. An apt metaphor in this case Sorting Claims and Descriptions might be the interaction between traditional medical systems and researchers seek- In emphasizing the particularity of each tra- ing to develop new pharmaceuticals. In dition’s approach to meditation, one need their search for plants whose active ingre- not discount the possibility that highly dis- dients might yield effective new medica- parate traditions may have independently tions, some researchers have begun exam- developed techniques that lead to similar ining traditional medical systems in various and measurable outcomes.2 Nevertheless, it cultures in order to narrow their search seems best not to begin with an assump- based on traditional claims about the medic- tion about any such innate similarity in inal properties of local plants (Jayaraman, disparate meditative traditions. One reason 2003; Schuster, 2001). In that collaboration, for avoiding such assumptions is the issue attention to the particularity of the heal- of particularity above, but another reason ing tradition is crucial, for it is the local is that similarities among traditions tend knowledge about specific, local plants that to appear primarily in claims about the will aid the search for new medications. ultimate meaning or nature of the state Clearly, such a project would be gravely hin- attained (e.g., “pure consciousness”) or in dered if researchers were to assume that, for metaphysically charged phenomenological example, an Amazonian healer’s traditional descriptions (e.g., ineffability) that do not herbal lore would somehow amount to the lend themselves to easy measurement or same traditional knowledge about medicinal interpretation. herbs that one would hear from a Himalayan Because similarities among traditions healer. The value of consulting a specific tra- often rest on such issues, an emphasis on dition is precisely that – through accident or those similarities tends to exaggerate a prob- expertise – the tradition may have gleaned lem that all researchers on meditation must some valuable knowledge or developed face; namely, the need to discern which some practice that is not found elsewhere. parts of a traditional account of meditation This importance of particularity supports are useful in formulating a neuroscientific the need to preserve local traditions, but it research strategy, as opposed to parts of an also speaks to the need to heed their bound- account that are not suitable for that pur- aries. A common problem with the literature pose. The problem here is the need to inter- on meditation is a tendency to ignore those pret traditional discourse about meditation, boundaries in order to emphasize some especially in terms of meditative techniques vague universality in human experience. and resultant states. In short, traditional acc- This attention to the particularity of con- ounts often describe techniques and resul- templative traditions is related to another tant states that are measurable and repeat- aspect of the approach we adopt; namely, able; nevertheless, parts of the same account that it is also strongly consistent with our may also focus on issues that can neither be knowledge of the neurosciences. Specifi- measured nor repeated. In many traditions, cally, cognitive and affective neuroscience the distinction between these parts of an has matured over the past decade, and we account reflects a tension between (1) close now understand something about the brain descriptions of meditative techniques and mechanisms that subserve different atten- states and (2) the metaphysical or soteriolog- tional and affective processes. Meditation ical requirements that must be met by those techniques that target specific underlying states, often expressed in textual sources that processes are thus likely to engage different the tradition considers inviolable. neural circuitry. If, however, the particular- Let us take as an example the Tibetan ity of a tradition’s claims and practices are practice of “Open Presence,” which we dis- not examined, the possibility that a practice cuss further below. In describing Open Pres- targets a specific process will not be noted. ence, traditional authors, such as Wangchug P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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Dorje(´ 1989) and Thrangu (Thrangu & John- dhism, most traditions use a term for med- son, 2004), offer typically detailed descrip- itation that correlates with the Sanskrit tions both of the techniques that induce that term bh¯avan¯a, literally, “causing to become.” state and also of the experiences that should In Tibetan traditions, the usual translation occur when the techniques are applied for bh¯avan¯a is gôm (sgom), which roughly properly.3 For example, discursive tech- means “to become habituated to” or “to niques for de-emphasizing the objectifica- become familiar with.” The meditative tration of sensory content are described in ditions of Tibetan Buddhism often employ detail, and in terms of resultant states, the the term in a generic fashion, and as a consequent loss of a sense of subject-object result, it is often translated into English with duality is also articulated clearly. These parts the equally generic term “meditation.” The of the traditional account lend themselves generic usage of gôm or “meditation” reflects to investigation, inasmuch as they describe its application to a remarkably wide range techniques and results for which neural of contemplative practices: For example, the correlates may be plausibly postulated and visualization of a deity, the recitation of a tested. At the same time, however, Buddhist mantra, the visualization of “energy” flowing philosophical concerns also demand that the in the body, the focusing of attention on the state of open presence reflects the onto- breath, the analytical review of arguments logical foundation of all reality, and Bud- or narratives, and various forms of object- dhist notions of nirvan¯ . a also require that the less meditations would all be counted as realization of that state will lead the adept “meditation.” to attain inconceivable physical and mental Nevertheless, despite this variety, it is powers. Such claims often occur in texts that possible to identify some relevant features traditional scholars are obliged to defend common to the traditional descriptions of under all circumstances. From a neuroscien- these Buddhist practices, especially when tific perspective, however, these claims do one separates those descriptions from meta- not lend themselves readily to analysis or physical arguments or exigencies that stem description. Thus, from the vantage point of from defending a textual tradition. First, it the researcher who stands outside the tra- is assumed that each such practice induces dition, it is crucial to separate the highly a predictable and distinctive state (or set detailed and verifiable aspects of traditional of states) whose occurrence is clearly indi- knowledge about meditation from the tran- cated by certain cognitive or physical fea- scendental claims that form the metaphysi- tures or events phenomenally observable to cal or theological context of that knowledge. the practitioner. Second, the state induced is said to have a predictable effect on both mind and body in such a way that, by Meditation as Explanandum inducing that state repeatedly, a practitioner Attention to the particularity of each tra- can allegedly use it to enhance desirable dition and the careful examination of tra- traits and inhibit undesirable ones. Third, the ditional knowledge about meditation both practices are gradual in the sense that the contribute to a main concern of this chapter: ability to induce the intended state is sup- the notion of meditation as an explanan- posed to improve over time, such that an dum. Or, to put the issue another way, experienced practitioner should meditate in how does one define “meditation” in the a manner that is superior to a novice. From context of neuroscientific study? This ques- the traditional standpoint, this improvement tion is not answered easily in part because is marked especially by two phenomenally of the extremely wide variety of human reportable features: the acquisition of cer- activities to which the term “meditation” tain traits (cognitive, emotional, or physical) might be applied. And the situation may and/or the occurrence of certain events (cog- not be much improved even if one focuses nitive, emotional, or physical). Finally, the on just one tradition. In the case of Bud- practice used to induce the state must be P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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learned, usually from a meditation teacher into a highly detailed scholastic tradition who is said to be a virtuoso in the practice. known in Sanskrit as the Abhidharma – That teacher will also serve as a guide to a type of Buddhist “psychology” that also the practice so as to assist the practitioner includes discussions of epistemology, philos- in improving his or her ability to produce ophy of language, the composition of the the state. material world, and cosmology.4 Based on these features, these diverse Despite the variety of Buddhist traditions, forms of Buddhist meditation may be taken they share two axioms articulated in Abhid- as explananda in regard to three general harma texts: A central goal of Buddhist prac- issues: (1) the claimed production of a distin- tice is the elimination of suffering, and any ctive and reproducible state that is phenom- effective method to eliminate suffering must enally reportable, (2) the claimed relation- involve changes in one’s cognitive and emo- ship between that state and the development tional states, because the root cause of suffer- of specific traits, and (3) the claimed pro- ing is a set of correctable defects that affect gression in the practice from the novice to all the mental states of an untrained person the virtuoso. Although initially formulated (Gethin, 1998). Thus, any practice that is in terms of Tibetan practices, these features considered by the tradition to be an effec- seem to be a useful way of understanding tive method must involve the features noted how meditative practices in most contem- above, including some set of reliable tech- plative traditions may be construed as neuro- niques that induce mental states that will scientific explananda. induce the desired changes in behavioral and psychological traits. In this regard, the Bud- dhist contemplative traditions exhibit con- A Paradigmatic Framework: Buddhist siderable diversity, because they hold diver- Meditative Techniques gent opinions about the precise nature of Our use of Buddhist contemplative tradi- the defects to be eliminated, the traits to be tions to develop a theoretical framework induced, and the best methods for accom- for understanding meditation is not merely plishing all this. At the same time, both the a product of historical accident; rather, diversity and the continuity of Buddhist con- Buddhist contemplative traditions are par- templative practices also stem from the rich ticularly well suited to the development of cultural context in which Buddhism initially this kind of theoretical model. The rea- flourished. son, in brief, is that unlike many contemplative traditions, Buddhist traditions tend early history and basic forms to offer extensive, precisely descriptive, and When the historical Buddha S´ akyamuni¯ first highly detailed theories about their prac- set out on the religious life (ca. 500 bce), tices in a manner that lends itself readily he apparently encountered a large number to appropriation into a neuroscientific con- of meditative techniques that were already text. This emphasis on descriptive preci- being practiced by various contemplative sion stems from the central role that various traditions in South Asia. Although histor- forms of meditation play in Buddhist prac- ical sources from this period are generally tice. That is, from the standpoint of nearly vague in their descriptions of contempla- every Buddhist tradition, some type of med- tive practices, one can identify some com- itative technique must be employed if one mon trends. Broadly speaking, these tra- is to advance significantly on the Buddhist ditions maintained that the contemplative spiritual path, and because Buddhism ini- life should be focused on the search for tially developed in a cultural context where one’s true self (often called the atman¯ ), and a wide range of such techniques were avail- because this true self was generally assumed able, Buddhist theoreticians recognized the to be somehow obscured by one’s involve- need to specify exactly the preferred tech- ment in the world of the senses, many con- niques. Their analyses eventually develop templative techniques involved an inward P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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focus whereby one’s mind was retracted lated as both “mindfulness” and “awareness”; from the senses. In addition to this inward in simple terms, it is the mental function focus, most techniques from this period (caitt¯asika) that focuses the mind on an probably sought to reduce the occurrence object. At the same time, the meditation of other types of mental content – generi- involves a faculty that checks to see whether cally called “conceptuality” (kalpan¯a) – that the smr.ti is focused on the intended object were also thought to obscure one’s vision or whether it has lost the object. Thus, of the true self. Distractions caused by the this other faculty, often called samprajanya, fluctuation of the mind were commonly involves a type of meta-awareness that is thought to be linked to the fluctuation of not focused on an object per se, but rather the breath, and meditative techniques there- is an awareness of that intentional rela- fore often involved either breath control tion itself (Gethin, 1998; Silananda, 1990; (pr¯an. ay¯¯ ama) or at least some attention to Wallace, 1999). the disposition of the breath. And because Both as a state and as a style of prac- the mind was thought to be strongly influ- tice, samatha´ provides the practical and enced by the body, contemplative practices theoretical underpinnings of many other involved specific postures or corporeal exer- Buddhist practices, especially because it con- cises (Bronkhorst, 1986; Gethin, 1998). stitutes the basic paradigm for any prac- When these practices were appropriated tice that involves one-pointed concentra- by the historical Buddha S´ akyamuni,¯ their tion (ek¯agrat¯a) on a specific object. At the overall context was altered, inasmuch as same time, however, Buddhist theorists who the Buddha maintained that the belief in discuss samatha´ generally do not consider a “true self” (¯atman) was completely mis- it to be in and of itself Buddhist. That is, taken. Indeed, from the earliest days a cen- practices oriented toward attaining samatha´ tral goal of Buddhist contemplative practice must create a highly developed ability to sus- is precisely to demonstrate to the practi- tain intense focus on an object, and whereas tioner that no such fixed or absolute iden- the development of that ability does lead to tity could ever be possible (Gethin, 1998). some trait changes, it does not lead to all of Nevertheless, although the Buddha altered the changes that Buddhists seek, most espe- the context of the contemplative practices cially in regard to the regulation of emotions. that he encountered, the Buddhist medi- Hence, although a samatha´ -oriented prac- tative techniques that he and his followers tice may be a necessary ingredient of most developed retained some of the same basic Buddhist contemplative traditions, it must principles of inward focus, reduction of con- be accompanied by another fundamental ceptuality, the importance of the breath, and style of Buddhist practice; namely vipa´syan¯a the relevance of the body. or “insight.” (Gethin, 1998; Silananda, 1990; Perhaps the most ubiquitous style of Bud- Wallace, 1999). dhist meditation that exhibits these features As with the samatha´ style of practice, is meditation aimed at improving concentra- vipa´syan¯a is also one of the earliest and tion – a style of meditation that is rooted in most fundamental forms of meditation. For practices aimed at obtaining samatha´ . Trans- Buddhist theorists, vipa´syan¯a is a style of latable literally as “quiescence,” samatha´ is meditation that, in combination with the a state in which the practitioner is able focus or stability provided by cultivating to maintain focus on an object for a the- samatha´ , enables the practitioner to gain oretically unlimited period of time. As a insight into one’s habits and assumptions term, samatha´ therefore can also describe about identity and emotions. In general, one of the historically earliest and most basic this insight includes especially the real- styles of Buddhist meditation that aims at ization of “selflessness” (nair¯atmya) – that attaining that state. In such a practice, the is, realizing that one’s belief in a fixed, practitioner augments especially a mental essential identity is mistaken and hence faculty known as smr.ti, confusingly trans- that the emotional habits that reflect that P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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belief are baseless (Dalai Lama XIV, 1995; titioner. This basic technique of recitation Gethin, 1998; Silananda, 1990). Neverthe- and visualization is representative of a wide less, although every Buddhist contemplative range of similar Buddhist practices that tradition would agree that such a realiza- evolved during the first millennium. Chief tion must be part of vipa´syan¯a, one again among these is the practice of visualiz- encounters considerable diversity in the pre- ing deities and paradisiacal environments, cise way in which vipa´syan¯a is defined and a technique especially important in most the way it is developed in practice. For exam- forms of Buddhist tantra (Beyer, 1977). ple, in some traditions reasoning and a type Alongside Recollection (and later, visu- of internal conceptual discourse are critical alization) practices, Lovingkindness medita- to the practice, but other traditions maintain tion was also a widespread practice in both that reason and concepts are of only limited early and later Buddhism, where it is thema- use in obtaining vipa´syan¯a. Likewise, some tized as the cultivation of “great compassion” traditions maintain that a vipa´syan¯a medi- (mah¯akarun. a)¯ . The practice aims to culti- tation must have an object toward which vate an emotional state; namely, a sense of some type of analysis is brought to bear love and compassion toward all living things. (Dalai Lama XIV, 1995; Silananda, 1990), Representative of a wide range of practices whereas others maintain that the meditation that promote or inhibit traits by repeatedly must eventually become completely object- inducing a particular emotional state, some less (Wangchug Dorje,´ 1989). Perhaps the forms of the practice involve the recita- sole theme that runs throughout all Buddhist tion/visualization techniques employed in traditions is that, in vipa´syan¯a meditation, Recollection meditation. Some discursive the type of meta-awareness mentioned ear- strategies, such as thinking through the steps lier plays an especially important role – an of an argument for compassion, may also issue that we examine in the section on the be employed (Dalai Lama XIV, 1991;P. theory of meditation. Williams, 1989). Last to develop (toward the end of the further historical developments first millennium in India) are a variety of Although the basic combination of samatha´ practices that may be called tantric Wind and vipa´syan¯a provides both a theoretical meditations. These practices aim to manip- and historical touchstone for the develop- ulate the various forms of energy, metaphor- ment of Buddhist contemplative practices, ically called Wind (v¯ayu), that are alleged a number of other forms of meditation to flow in channels throughout the body. were developed in the various Buddhist This model is roughly analogous to the con- communities of Asia. Three practices ini- temporary understanding of the nervous sys- tially developed in India are especially tem, where the notion of Wind is analo- emblematic of the range of developments: gous to the propagation of neural impulses. “Recollection of the Buddha” meditations In the Buddhist model, the mind itself is (buddh¯anusmr.ti), Lovingkindness medita- thought to consist of such Wind energy, tion (maitr¯ıbh¯avan¯a), and tantric “Wind” and practices that manipulated that energy (v¯ayu) meditations. were therefore intended to induce or inhibit The practice of Recollection of the Bud- mental states or traits. The many techniques dha is probably, along with Lovingkindness employed include the visualization of vari- meditation, one of the oldest Buddhist prac- ous syllables or other items at specific points tices. Recollection involves the recitation of in the body as a means to alter the flow of the Buddha’s attributes, and in its earliest mental energy; physical exercises, including form it may have involved nothing more breathing exercises; and an array of other than that. At some point, however, the techniques, including manipulation of the recitation of the Buddha’s physical attributes diet. An example of this style of practice was linked with the visualization of the that later becomes important in Tibet is the Buddha in the space in front of the prac- “Tummo” (gtum mo) practice – a method P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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that, in manipulating the Wind, is also said to stood to describe two aspects of the same med- generate considerable body heat as a byprod- itative state. In the interest of both applica- uct (Cozort, 1986; Dalai Lama XIV, 1995; bility and simplicity, we derive our account English, 2002; Snellgrove, 2002). primarily from a specific and living contem- As Buddhism spread from its initial loca- plative tradition: Tibetan Buddhism. tion in the Gangetic plain, Buddhist practi- Drawing on a maxim developed by tioners developed and enhanced the above their Indian predecessors, Tibetan theorists practices, along with many other related maintain that the highest forms of Bud- forms of meditation. Eventually, Buddhism dhist meditation must integrate the quali- spread to other regions of Asia, and vari- ties of samatha´ and vipa´syan¯a into a sin- ous traditions arose that persist to this day. gle practice. As described by the most Each tradition elaborated its own particular common traditional metaphor, the prac- interpretation of techniques that, although titioner cannot make significant spiritual likely inherited from Indian Buddhist tradi- advancement without the combination of tions, always acquired a local flavor. Never- samatha´ and vipa´syan¯a, just as a cart cannot theless, most extant practices reflect the var- move without two wheels. Another tradi- ious styles of meditation noted above. tional metaphor is perhaps more descriptive: When attempting to see the murals on analysis of meditation: samatha and the wall of a dark cave, one must use a vipasyan´ a¯ as paradigm lamp that is both well shielded and bright. To aid in the mastery of meditative tech- If the lamp is not well shielded, then its niques – and also to respond to critics out- flame will flicker or even become extin- side their traditions – Buddhist theoreticians guished, and if its flame is not sufficiently in India and elsewhere developed detailed intense, the lamp’s light will be insufficient accounts of their contemplative practices. for the task at hand (Tsongkhapa, 2002). These accounts are often extremely com- This very basic metaphor describes the qual- plex, and as noted above, they sometimes ities that are indicated by the terms samatha´ raise metaphysical issues that are not eas- and vipa´syan¯a: The former primarily con- ily addressed in neuroscience. Likewise, to cerns the stability (gnas cha) of the medita- some degree the accounts are shaped by the tive state, whereas the latter concerns that need to defend a particular textual tradition state’s phenomenal or subjective intensity or line of argumentation, and as a result, (gsal cha) (Thrangu & Johnson, 2004). some statements that seem to be descrip- To state these features more precisely, in tive are not known to be exemplified by any meditations that involve an object, stability actual Buddhist practice. Nevertheless, other refers to the degree to which the practitioner aspects of the accounts seem more empiri- is able to retain focus on the object with- cal in their approach, and attention to those out interruption. In such meditations, clar- aspects may prove useful when examining ity refers to the sharpness or vividness of the meditation in a laboratory context. With appearance of the object in awareness. For this in mind, we have sketched the follow- example, in the visualization of a colored ing practical and simplified account of Bud- disc, a completely stable meditation would dhist meditation theory, aimed especially at be one in which the meditator’s focus on the researchers interested in studying contem- object is not perturbed at all by other phe- plative practices in Buddhism and other tra- nomenal events, such as emotions, thoughts, ditions. As one might expect, the numerous or sensory perceptions. In such a meditation, forms of Buddhist meditation are accompa- the clarity would be constituted by the disc’s nied by an equally wide range of theoreti- vividness of color and sharpness of shape. cal accounts. Nevertheless, the central issues Generally, these two aspects of a medi- can be addressed in terms of the theories that tative state are understood to work some- undergird samatha´ and vipa´syan¯a, especially what at odds with each other in the case when these styles of meditation are under- of novice meditators. That is, in the case P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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of a novice, the greater the stability of the worth noting that, just as the tradition con- meditative state, the more likely is it to lack tains techniques to ease mental or physical intensity. And the greater its intensity, the tension, it also espouses methods to coun- more likely is its lack of stability. This tension teract an excess of relaxation or dullness between stability and clarity is expressed in (Thrangu & Johnson, 2004; Tsongkhapa, the two main flaws that hinder a meditation: 2002; Wangchug Dorje,´ 1989). “dullness” (Tib., bying ba) and “excitement” Although the balance of clarity and sta- (Tib., rgod pa). When dullness first arises, the bility as described above forms an overall focus on the object will be retained, but as paradigm for Tibetan Buddhist practices, it dullness progresses, the clarity of the object is important to recognize the ways in which becomes progressively hindered, and a sen- that paradigm is modified for each practice. sation of drowsiness overtakes the medita- For example, novices hoping to develop the tor. If dullness continues, the dimness of the meditative state of Rigpa Chôgzhag or “Open object will cause the meditator to lose focus Presence” may be taught to emphasize one on it, or in the case of gross dullness, the or another feature in order to make ini- meditator will simply fall asleep. In contrast, tial headway in the practice. In short, they when excitement occurs, the clarity of the are encouraged to err on the side of clar- object will often increase, but the intensity ity, because it is more important to avoid of the mental state perturbs the meditation dullness than excitement in the early stages such that distractions easily arise and focus of that practice (Thrangu & Johnson, 1984; on the object is lost (Thrangu & Johnson, Wangchug Dorje,´ 1989). 2004; Tsongkhapa, 2002; Wangchug Dorje,´ The practice of Open Presence raises 1989). another issue: the applicability of this model In most practices, the ideal meditative to meditations that do not focus on an state – one beyond the novice stage – is a object. In objectless practice, the loss of state in which neither dullness nor excite- focus on the object or its degree of phenom- ment occurs; in short, stability and clarity are enal vividness obviously cannot be taken as balanced perfectly. Hence, for the Tibetan criteria for the degree of stability or clarity. contemplative traditions (and indeed, for Instead, stability becomes a marker for the nearly every other Buddhist tradition), it ease and frequency with which the medita- would be incorrect to interpret Buddhist tor is perturbed out of the state the medita- meditation as “relaxation.” This is not to tion is intended to induce, and clarity refers deny the importance of mental and phys- to the subjective intensity of that induced ical techniques that help the practitioner state. Thus, after a session of Open Presence, relax. Without such techniques, an excess a meditator who reports that the medita- of physical or mental tension may develop, tion was unstable but very clear would mean and when such tension occurs, excitement that, although the intended state was inter- will almost certainly arise. If, however, such rupted repeatedly, the subjective experience relaxation techniques are overused, they of the state was especially intense when it are likely to propel the practitioner into occurred. dullness and hence hinder the meditation. A final aspect of the basic theory of med- Indeed, from a Buddhist perspective a prac- itation concerns the distinction between the tice that only relaxes the mind might even- actual meditative state (Tib., dngos gzhi) and tually prove harmful. That is, such a practice the post-meditative state (Tib., rjes thob). would develop a great deal of dullness, and In brief, the states developed in medita- as a result the practitioner might become tion are usually thought to create a post- withdrawn, physically inactive, and mentally meditative effect. In some cases, some phe- depressed. Overall, then, Buddhist medi- nomenal aspect of the meditation persists tations avoid an excess of relaxation, and in the post-meditative state. For example, it is for this reason that very few prac- after a meditation in which one cultivates tices are done while lying down. It is also the experience of phenomenal content as P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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seeming dreamlike, one’s perceptions in the larized set of meditation instructions avail- post-meditative state are also said to have able to a wide population that is not lim- a dreamlike quality for at least some period ited to celibate monastics (Coleman, 2002). after arising out of meditation. In other cases, In its most typical form, the early stage of the post-meditative state involves a trait Vipassana¯ practice consists largely of a basic change. Meditation on love and compassion, samatha´ style of meditation focused on the for example, is alleged to inhibit the occur- sensation made by the breath as it flows in rence of anger between meditative sessions. and out of the nostrils, although sometimes From the Buddhist theoretical perspective, another aspect of the breath may be taken such post-meditative changes are often at as the object of meditation (Gunaratana, least as important as the states induced dur- 2002). In the early stages, the aim of the ing the meditation itself, and success in a meditation is to keep the attention focused practice is often measured by the strength of on the breath without distraction – that is, the effects that occur after meditation (Dalai without the attention wandering to some Lama XIV, 1995; Thrangu & Johnson, 1984; other object, such as a sensation or a mem- Tsongkhapa, 2002; Wangchug Dorje,´ 1989). ory. For beginners (and even for advanced practitioners), the attention inevitably wan- contemporary practice and ders, and the usual instruction is to recog- problems of terminology nize that the mind has wandered – for exam- In the laboratory setting neuroscientific ple, to see that it is now focused on the pain researchers are likely to encounter Bud- in one’s knee, rather than on one’s breath – dhists who engage in contemplative prac- and then to “drop” or “release” the distrac- tices located in three overall traditions: the tion (the knee pain) and return to the breath. Vipassana¯ or Insight Meditation movement Part of the aim is not only to develop focused located within Theravada¯ Buddhism, the attention on the breath but also to develop Zen tradition of Japan, and the Tibetan tra- two other faculties: a meta-awareness that dition. One might encounter practices from recognizes when one’s attention is no longer other Buddhist traditions, but the medi- on the breath and an ability to redirect tations of the aforementioned three tradi- the attention without allowing the meta- tions are by far the most widespread. They awareness to become a new source of distrac- are also the most likely to be practiced tion, as when one berates oneself for allow- by persons, such as Europeans and North ing the mind to wander (Gunaratana, 2002; Americans, who are not native to the cul- Kabat-Zinn, 2005). tures in which the practices have devel- Given the description thus far, practices oped (Coleman, 2002). Of these three tra- very similar to Vipassana¯ meditation are also ditions, the style of meditation taught in the found among contemporary practitioners of Vipassana¯ traditions is especially emblem- Zen and Tibetan Buddhism. Indeed, it is pos- atic, because the basic meditative style of sible that the Vipassana¯ approach to medi- Vipassana¯ closely resembles some founda- tation on the breath has led Zen and Tibetan tional practices in the Zen and Tibetan practitioners to employ a similar style of traditions. breath-meditation to a much greater extent The Vipassana¯ or Insight Meditation than they have in the past. Certainly, it is movement consists of several loosely allied clear that in contemporary Zen and Tibetan institutions and individuals that teach a practice, focusing the attention on the breath style of meditation rooted in the older (or sometimes another static object) is often contemplative traditions of Theravada¯ Bud- used as a means to develop the basic dhism in Myanmar, Thailand, and Sr´ ¯ıLanka.˙ level of concentration required for more Although it draws on older traditions, the advanced forms of meditation. In many Vipassana¯ movement is “modern” in that cases, these more advanced meditations aim it makes a somewhat simplified and regu- to enhance the type of meta-awareness that P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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is cultivated during the Vipassana¯ style of selves used as a means to thoroughly develop practice, and because the traditions have meta-awareness (samprajanya or praj˜n¯a) at different ways of understanding and enhanc- a later stage in the practice (Gunaratana, ing that meta-awareness, all three kinds of 2002). It is therefore not surprising that traditions – Vipassana,¯ Zen, and Tibetan smr.ti becomes closely associated with the Buddhism – diverge in their practices from meta-awareness, but this imprecise use of this point forward. smr.ti has contributed to the confusion con- Although Vipassana¯ meditation may be cerning the English terms “mindfulness” and especially representative of a widespread “awareness.” and foundational style of practice in contem- To restate the problem using the terms porary Buddhism, any discussion of Vipas- discussed earlier, we should note that such sana¯ meditation must address a problem authors as Thrangu (Thrangu & Johnson, of terminology: the often confusing use of 2004) employ the term “mindfulness” to the terms “mindfulness” and “awareness.” refer to the samatha´ aspect of a meditative In the Mindfulness-Based Stress Reduction practice – that is, the stability of the medita- (MBSR) designed by Jon Kabat-Zinn (2005), tion. And these authors then use “awareness” for example, the term “mindfulness” is used for the vipa´syan¯a aspect of the practice; that primarily to refer not to the focusing aspect is, the meta-awareness that is especially asso- of mind, but rather to the meta-awareness ciated with the clarity of the meditation. that surveys that focus and its relation to Turning then to its usage in, for example, the intended object. Likewise, in MBSR MBSR, one ﬁnds that mindfulness refers pri- the term “awareness” sometimes seems to marily to the vipa´syan¯a aspect of the prac- stand primarily for attention or the focusing tice, not the samatha´ aspect. aspect of mind. In contrast, popular works Although this problem is simply one of on Tibetan Buddhist meditation, such as terminology, it can prove quite confusing in a the work of Thrangu (Thrangu & Johnson, laboratory setting. In the case of Open Pres- 2004), use these same two terms, but their ence practice, Tibetan meditators will usu- meaning is reversed: “mMindfulness” refers ally deny that their practice is of mindfulness to attention or focus, whereas “awareness” (i.e., dran pa’i nyer gzhag), whereas in fact, refers to a faculty of mind that surveys the they mean to say that they are emphasizing mental state at a meta-level. the development of some meta-awareness in The confusion in English terminology a way that has many parallels with the mind- is in part due to some confusion in the fulness practice of Vipassana¯ meditators or proper usage of the Buddhist technical terms persons trained in MBSR. For the researcher, themselves. Strictly speaking, smr.ti – liter- one solution to this problem is again to be ally, “memory” – is the focusing aspect of attentive to the particularities of the practice mind, and historically it is often translated in question while keeping track of the fact as mindfulness when used in the context that we have yet to standardize the English of meditation. An obvious case is the com- lexicon of technical terms for the analysis of mon technical term smr.tyupasth¯ana (in Pali,¯ meditation. satipat..th¯ana), usually rendered as “founda- Another problem of terminology comes tion of mindfulness.” The problem, how- with the use of the term samatha´ itself, espe- ever, is that even though smr.ti should stand cially in its Tibetan context. Our discus- only for the focusing aspect of mind, in both sion thus far has used the term samatha´ in popular and technical Buddhist literature on three basic meanings: (1) a particular state in meditation it is not infrequently assimilated which one can allegedly focus on an object to the meta-awareness mentioned above. for an unlimited period of time, (2) a style One reason for this is that in the Vipassana¯ of practice aimed at attaining that state, and tradition, meditations that initially empha- (3) the aspect of any meditative state that size smr.ti as the focusing faculty are them- constitutes its maximal stability. Already, P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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these three meanings can lead to consid- ing meditation, it may be more useful to use erable ambiguity, but the second meaning other Buddhist terms as labels for a partic- is particularly troublesome. One problem is ular practice – or perhaps researchers will simply that the expression “samatha´ medi- develop new terms in dialogue with practi- tation” is not sufficiently clear. That is, when tioners. Otherwise, if one is not careful, one Buddhist theorists are being precise, they may be misled into believing that a wide set recognize that samatha´ meditation should of disparate practices are the same because, be rendered more properly as “meditation for one reason or another, they may all be aimed at obtaining samatha´ .” called “samatha´ meditation.” But even after this clarification, a problem remains: When one practices samatha´ meditation, which kind of samatha´ is one trying Three Meditative States in to obtain? In other words, is one attempt- Tibetan Buddhism ing to cultivate the ability to concentrate on an object for an unlimited period? Or is one We have mentioned repeatedly the impor- trying to cultivate some other kind of maxi- tance of attending to the particularity of mal stability? The main problem here is that, the contemplative tradition whose practices in the Tibetan context, the term samatha´ is might become part of a research agenda, and used to refer to stability in meditations that with this in mind, we now discuss briefly do not even have an object; hence, in those three specific forms of meditation found in cases samatha´ cannot relate to concentra- Tibetan Buddhism. Part of our aim is to set tion on an object. To make the matter even the ground for a discussion of these prac- more complicated, there are Tibetan practices, because they have already been the tices in which samatha´ is used in connection subjects of some preliminary neuroscientific with both kinds of meditations (i.e., with research, as is presented below. an object and without an object). Finally, All three styles of meditation come from even when samatha´ is related to practices a particular strand of contemplative prac- with an object, the object in question may tice in contemporary Tibetan Buddhism. differ considerably; an example with neuro- In Tibetan, a term for this style of prac- scientific import is the difference between tice is Chag-zôg (phyag rdzogs), a compound focus on the breath and focus on a visualized that refers to two traditions of meditation: object. Indeed, traditional scholars, such as the “Great Seal” or Chag-chen (phyag chen; Thrangu (Thrangu & Johnson, 2004,p.21), Skt. Mah¯amudr¯a) of the Kargyu¨ (bka’ with all these issues in mind, caution their brgyud) school and the “Great Perfection” students about the potential for confusion or Dzôg-chen (Karma Chagme,´ 2000)ofthe caused by the ambiguity of technical terms Nying-ma (Rnying ma) or “Ancient” school. such as samatha´ . Although historically and institutionally dis- As with the case of mindfulness and tinct, for the last 200 years the Great Seal awareness, the problems with the term and Great Perfection traditions have become “samatha´ ” should remind researchers that allied so closely that it is now exceedingly the particularities of a practice may rare to find a practitioner who employs the be obscured by ambiguous terminology, techniques of only one style in complete whether in the source language or in English isolation from the techniques of the other translation. As a practical matter, one may style. This is not to say, however, that there even wish to avoid the term samatha´ as a are no important differences between these description of a practice. This is not to say two traditions. They differ especially in the that the term should be abandoned: Clearly, details of their most advanced practices, and for both historical and theoretical reasons, they also propose slightly different tech- samatha´ must remain in the lexicon on Bud- niques for the three meditations discussed dhist meditation. But when seeking to spec- below. Nevertheless, for the purposes of the ify exactly what a practitioner is doing dur- brief descriptions below, they may be treated P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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as constituting a single overall style of con- ment in developing the ability to concentrate templative practice. on an object (Thrangu & Johnson, 2004; The three practices in question are Tsé- Tsongkhapa, 2002; Wangchug Dorje,´ 1989). cig Ting-ngé-dzin (rtse gcig ting nges ‘dzin) One aspect of setting is the context formed or Focused Attention, Rig-pa Chôg-zhag (rig by the other practices in which a medita- pa cog bzhag) or Open Presence, and Mˆıg- tor is engaged. These practices include espe- mé Nying-jé (dmigs med snying rje) or Non- cially formal guidance received from one’s Referential Compassion. All meditators in preceptor, the study of Buddhist thought, the Chag-zôg style receive at least some a wide range of devotional practices, and instruction in all three of these practices, and the observance of a basic moral code based all advanced meditators will be thoroughly upon non-harm (ahim. s¯a) and compassion. familiar with them. Another aspect of setting concerns the site where one is to meditate. In this regard, tra- focused attention (tse-cig´ ditional accounts speak at length about the ting-nge-dzin´ ) need for a quiet place with few distractions The Tibetan term Tsé-cig Ting-ngé-dzin or and adequate access to food and water. So “Focused Attention” refers to a mental state too, the spot to be used for meditation is in which the mind is focused unwaveringly prepared by the meditator on a daily basis and clearly on a single object. This state, by cleaning it and preparing it through vari- which literally translates as “one-pointed ous ritual activities. concentration,” occurs in many practices, Once preparations for the session are and it is a typical goal for novices in the complete, the meditator adopts the posture Chag-zôg traditions. The relevant Buddhist for meditation. Various styles of Tibetan theories and techniques are usually drawn meditation involve different postures, but in from a generic account of practices that the context of developing Focused Atten- seek to develop samatha´ in the sense of tion, the general rule is that the spine the ability to focus on an object for an must be kept straight and that the rest unlimited time. This generic account, some- of the body must be neither too tense times called “common samatha´ ” (thun mong nor too lax (Thrangu & Johnson, 1984; gi zhi gnas), differs from the present con- Tsongkhapa, 2002; Wangchug Dorje,´ 1989). text. That is, in actual practice, Chag-zôg At this point, another element of the practitioners of Focused Attention usually setting – the use of memorized formulas develop a lesser (and often unspecified) state to induce the proper conceptual attitude – of concentration before being instructed by is invoked, and depending on the practice their teachers to move on to other prac- in question, a number of other practices or tices, which no longer involve focusing on ritual activities may precede the portion of an object (Thrangu & Johnson, 2004). Nev- the practice in which one seeks to develop ertheless, the practice of cultivating Focused Focused Attention. Attention draws heavily on the theories and When actually engaged in the practice techniques of common samatha´ . Perhaps of Focused Attention, the meditator focuses the most important principles drawn from the mind on the object to be meditated that generic account can be summarized upon. This object may be a sensory object, under six overall issues: the setting, the body such as a visible object in front of the med- posture, the object, the flaws that hinder itator, or it might be mental, such as a visu- progress, the “antidotes” to the flaws, and alized image (Thrangu & Johnson, 2004; the stages of development in meditation Wangchug Dorje,´ 1989). In general, Tibetan (Tsongkhapa, 2002). practitioners do not use the breath as an Although sometimes neglected in schol- object of meditation, except perhaps for rel- arly work on Buddhist meditation, the set- atively brief periods as a means to settle the ting for meditation is clearly considered by mind (Thrangu & Johnson, 2004). This trend traditional authors to be an important ele- may be changing, however, in part because P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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of the modern encounter with other Bud- counteract excitement and allow the medi- dhist traditions. To a great extent, the par- tator to return to the original object of med- ticular object chosen depends largely on the itation (Wangchug Dorje,´ 1989). particular practice (such as tantric visual- In terms of dullness, methods to counter- ization or Open Presence) that forms the act it are often related to those that coun- overall context for the development of Focu- teract excitement. For example, just as one sed Attention. might counteract excitement by meditating Having placed the attention on the object, in a dimly lit room, one can counteract dull- the meditator then seeks to avoid two over- ness by meditating in a brightly lit setting. all flaws: dullness and excitement. As men- So too, adding tension to the body or inten- tioned above, in the early stages, these flaws sity to a visualized object can also coun- manifest in a straightforward fashion. Dull- teract dullness. And in terms of affective ness is detected by, for example, a dim- methods, the meditator might temporarily ming or blurring of the object and, in its contemplate joy or compassion (and some- most gross form, a sensation of drowsi- times even fear) so as to energize the mind ness. The main symptom of excitement is enough to return to the original object. As distraction (i.e., the intensity of the focus with excitement, visualizations may also be causes one to be hyperaroused, and as a employed; for example, one may visualize result, attention wanders to other mental a white dot on one’s forehead at the point content or phenomena; Thrangu & Johnson, between the eyes (Wangchug Dorje,´ 1989). 1984; Tsongkhapa, 2002; Wangchug Dorje,´ For advanced meditators, many of the 1989). “antidotes” mentioned here are too coarse, In practice, the usual technique to coun- and they would lead to an overcorrection in teract excitement is to become aware of the the meditation. For these practitioners, the occurrence of the distracting content or phe- subtle degree of dullness or excitement that nomenon – that is, one notes the fact that the they encounter is corrected by equally sub- mind is now attending to another object, and tle adjustments to the clarity (for dullness) then one returns the mind to the intended or the stability (for excitement) of the med- object without allowing the original distrac- itation state until both stability and clarity tion to produce more mental distractions, reach their maximal, balanced state. such as the thought, “It is not good to be dis- The notion that advanced meditators tracted” (Thrangu & Johnson, 2004). Some- employ different responses to flaws in med- times excitement is also caused by physical itation raises the final relevant issue in or environmental factors – too much ten- traditional accounts; namely, the theories sion in the body or too much bright light in about the progression of stages in medita- the meditation area, for example. Or, excite- tion. Many contemplative traditions speak ment may be caused by applying too much of ascending stages through which the prac- effort to the meditation (i.e., being too rigid titioner passes; a typical account speaks of in one’s focus). Similarly, in the case of visu- nine levels of progressively higher degrees alized objects, excitement might be caused of concentration along with corresponding by too much intensity or brightness in the changes in the meditator’s response to dull- visualized object. Sometimes an affective ness and excitement (Thrangu & Johnson, remedy is used; for example, the meditator 1984; Tsongkhapa, 2002; Wangchug Dorje,´ might temporarily switch to a contempla- 1989). This schema, however, is far more tion of suffering, and the affective impact complicated than it seems, and as Apple of that contemplation will reduce excite- (2003) demonstrates, the Buddhist pen- ment enough that one can return to the orig- chant for scholasticism makes this topic an inal object of meditation. Various visualiza- extremely complicated one when it is con- tions – such as visualizing a small black drop sidered in its fullest form. Without going behind the navel – may also be employed to into great detail, it is important to note that, P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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according to these schemas, a single prac- counteracts flaws by seeing the true nature of tice may progress gradually through a num- identity and objects. And because the prac- ber of meditative states, but some of those tice involves many discursive strategies that states might differ significantly from each are based upon an underlying theory, one other both phenomenally and in terms of the must have some sense of those theoretical appropriate technique to be applied. Like- underpinnings. Hence, even though our pre- wise, the mental and physical effects of a sentation aims to focus on empirical descrip- practice may build gradually; for example, tions of what practitioners actually do, a brief as one’s level of concentration improves, foray into more abstract theory is neces- mental and physical well-being is also said sary. Our theoretical discussion is based on to increase But some effects occur only at three authors who are typical of the Chag-zôg some stages and do not progress further traditions: Karma Chagme(´ 2000), Thrangu (Tsongkhapa, 2002). (Thrangu & Johnson, 2004), and Wangchug In terms of the most relevant effects that Dorje(´ 1989). Our concise and thematic pre- are traditionally expected to arise from this sentation, however, might not be satisfac- practice, the main result of Focused Atten- tory to a strict traditionalist, in part because tion is a greater ability to concentrate and the issues involved are notoriously difficult a concomitant decrease in susceptibility to to explain. Nevertheless, from an academic being perturbed out of a concentrated state. and anthropological standpoint, this presen- The practice is also thought to increase not tation should suffice to convey the main the- only the stability of one’s concentration but oretical issues relevant to this style of con- also its intensity. At the higher levels of prac- templation as it is practiced currently. tice, this type of meditation is also said to Theoretical Background. When justifying reduce the need for sleep, and during the and explaining the types of practices that meditation it is thought to induce pleasur- induce Open Presence, Chag-zôg theorists, able sensations, including a lightness or pli- such as Karma Chagme(´ 2000), Thrangu ancy of mind and body. (Thrangu & Johnson, 2004), and Wangchug Dorje(´ 1989), argue that, properly speaking, open presence (rig-pa chog-zhagˆ ) objects are only known through experience; Open presence or Rig-pa Chôg-zhag is one it is nonsensical to speak of objects sepa- of the main meditative states that practition- rate from experience. Likewise, experience ers following the Chag-zôg style of practice of an object necessarily involves a subject attempt to cultivate. The basic motivation that experiences the object, and it is there- for the practice is rooted in a Buddhist axiom fore nonsensical to speak of objects without mentioned earlier: Namely, that one’s neg- speaking of a subject. The theoretical linch- ative emotional habits and behaviors arise pin is that the nature of both objects and from a set of mental flaws that cause one subjects is that which characterizes them to consistently misconstrue both one’s iden- under any circumstances – it must be essen- tity and also the objects toward which those tial to them, rather than accidental. And emotions and behaviors are directed. As what is essential to them is that they always noted above, those flaws are meant to be occur within experience. Hence, to know the corrected by vipa´syan¯a meditation through nature of objects and subjects is to know the which one cultivates an accurate under- nature of experience (Thrangu & Johnson, standing of the nature of one’s identity and 2004). the nature of objects in the world. In this Whatever may be the philosophical mer- sense, Open Presence may be considered its of such an analysis, Chag-zôg practi- a particular version of vipa´syan¯a. Chag-zôg tioners are thus aiming to understand the theorists, however, have a unique under- nature of experience – that which is essen- standing of what it means to gain the under- tial to any instance of experience, regard- standing or “wisdom” (Tib. ye shes) that less of the accidental and changing features P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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of the objects or subjectivities involved. To the process or occurrence of that experi- do so, they employ a set of techniques ence either passively or involuntarily. For that are intended to make the practitioner Chag-zôg theorists, this faculty of appercep- aware of the invariable feature of all expe- tive presentation is a derivative form of the riences. They speak of this invariable fea- more fundamental Awareness that is the ture using various descriptions, including basic nature or structure of consciousness Rigpa, “Awareness,” or, using the metaphor itself. Hence, a meditative technique that of light, Selwa (gsal ba), “Luminosity” or removes the cognitive features that usually “Clarity.” But whether called Awareness, obscure the implicit reflexivity of experience Clarity, or some other synonym, the point is one that moves that practitioner closer is that the invariant element in experience is to an understanding of that fundamental that which, from a phenomenal standpoint, Awareness. makes it possible for the subject-object rela- Above we noted that even the earli- tion to be presented in experience. est forms of vipa´syan¯a meditation seem to As the alleged invariant in all states of involve some form of meta-awareness that knowing, Awareness contrasts with features surveys the meditative state in such a way that are accidental (i.e., not essential) to that it enables one to know whether one any given cognition; namely, the particu- has lost the focus on the object. Likewise, lar features of the object and subject occur- that same type of meta-awareness serves ring within the cognition. What is accidental to determine whether or not dullness and about the object are its characteristics, such excitement are occurring. Thus, even in as color or shape. And what is accidental these other forms of vipa´syan¯a practice, one about a subject is, for example, its temporal encounters a type of reflexivity, inasmuch location in the narrative of personal iden- as the meditative state is meant to involve tity or the particular emotional state that an awareness of the state itself. With this in is occurring with the subjectivity. Hence, a mind, one can think of the Chag-zôg prac- meditative technique that enables the practice of cultivating Open Presence as empha- titioner to know Awareness or Clarity must sizing this aspect of vipa´syan¯a practice to somehow avoid attending to the particular- its furthest possible point. This practice dif- ities of object and subject and grant access fers from other meditations, however, in that instead to the fact of knowing itself. The theoretically it is taking an implicit aspect of problem, according to Chag-zôg theorists, is all cognitions – a fundamental form of reflex- that untrained persons are deeply entangled ivity – and making it phenomenally accessi- in the accidental features of experience; gen- ble to the practitioner. erally, they focus especially on the features of On this theoretical understanding of the object, and occasionally they are explic- Open Presence, two features of the practice itly aware of themselves as subjects. But in are especially salient. First, in other medi- either case, untrained persons are not aware tations that fall under the general rubric of of what is invariant in those experiences. vipa´syan¯a, one cultivates a faculty of mind To overcome this problem, the various that is best described as a meta-awareness; lineages of contemplative practice that fall it is “meta” in that it is dependent upon the under the rubric of Chag-zôg propose dis- mindfulness (smr.ti) that is focusing the mind tinct techniques, but one common approach on the object at hand. As noted above, this is based upon a move toward subjectivity meta-awareness surveys the mind itself so as in meditation. The notion here is that the to determine, for example, whether it is dull invariant aspect of experience is closely tied or excited. Thus, inasmuch as it focuses on to the reflexive awareness (Tib. rang rig) that cognition itself, the meta-awareness is reflex- enables one to have memories of oneself as ive, and to this degree it resembles the type an experiencing subject. On this theory, as of state cultivated in the practice of Open an object is being presented to an experienc- Presence. The difference, however, is that ing subject, reflexive awareness also presents in Open Presence the prefix “meta” would P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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be inappropriate; instead, it is assumed that, rather then being attendant upon the basic faculty of mindfulness – i.e., the faculty that focuses on an object – the reflexive aspect of mind is actually more fundamental than mindfulness. In other words, mindfulness must occur with an object, but the possibility of objects being presented in experience is itself rooted in a more fundamental reflexivity. The second distinctive aspect of Open Presence is that, unlike other meditations, at advanced stages of the practice there is no attempt either to suppress or to cultivate any particular mental content. One does not fo- Figure 19.1. cus, for example, on a visualized image or on a sensory object, such as a sensation made by This diagram is based especially on the the breath. In this sense the state of Open styles of Chag-zôg practice exemplified by Presence is objectless. Nevertheless, even Karma Chagme(´ 2000), Thrangu (Thrangu though higher levels of the practice do not & Johnson, 2004), and Wangchug Dorje´ involve any particular content or object, it (1989),and their works are the main tex- also is important for content to be occurring tual sources for the presentation below. in the mind because to cultivate an aware- It is important to note, however, that ness of the invariant nature of experience, the diagram suggests a trajectory of actual one must be having experiences. Indeed, for practice that, although clearly implicit in beginners it is preferable that the experi- these authors’ writings, is not explicit. ences be especially striking or clear. Thus, Nevertheless, this way of presenting the even though the meditation is objectless, it flow of the practice has the advantage of is not a state of blankness or withdrawal. Sen- being far less complicated than traditional sory events are still experienced, sometimes presentations. even more vividly. In terms of technique, this As Figure 19.1 illustrates, in this style of facet of the meditation is indicated by the practice the overall trajectory begins with a fact that one meditates with the eyes open meditation that develops concentration on and directed somewhat upward. an object. One then employs techniques Basic Practice. The actual state of Open that cultivate an awareness of subjectivity Presence is one in which the meditator in a manner that de-emphasizes the object. is aware of the Clarity or Awareness that In doing so, one gains phenomenal access makes all cognitions possible. This state is to the reflexive awareness that is thought a relatively advanced one, and even experi- to be invariant in cognition. One then de- enced practitioners may not be able to sus- emphasizes subjectivity as well so as to fur- tain it for more than a short period of time. ther enhance that access to reflexivity, and There are, however, a series of practices that finally one practices so as to move to the train inexperienced meditators to cultivate point where the invariant aspect of aware- Open Presence, and even experienced prac- ness is realized fully in meditation. Through- titioners sometimes modulate their practice out this entire process the close guidance of so as to move up or down the scale of prac- an instructor is considered essential. tices, depending on how well the particular This style of practice generally begins session is proceeding. with the development of Focused Attention Schematically, we use the diagram in Fig- (i.e., concentration on a particular object ure 19.1 to summarize the stages of the style as described previously). Initially retaining of practice that leads to Open Presence: some focus on the object, one then cultivates P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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attention to the state of the subjectivity often employed in oral instructions, one is observing the object. This is in part accom- not to “follow along” (rjes su ’brang ba) a plished by discursive strategies that are chain of thoughts. A much subtler indica- implemented after a certain level of concen- tion of grasping, however, is simply the fact tration and mental calm has been reached. that, in phenomenal terms, the appearance In one such strategy, one is instructed to ask or event seems separate from the subjectivity questions about the object, such as, “Is it in the experience. Thus, when one “releases” inside the mind or outside the mind?” Or, objects, one must do so with the understand- when an appearance arises, one observes it ing that the objects actually are not sepa- and asks, “Where did it arise from?” Or as rate from awareness itself, of which the sub- it abides in the mind, one asks, “Where is jectivity is also just a facet. This attitude is it abiding?” Or as it disappears, one asks, initially developed through discursive strate- “Where did it go?” These questions and sim- gies, which seem to play a crucial role in ilar discursive strategies are used to train developing Open Presence. one to see the object as just a phenom- Having become adept at emphasizing enal appearance and to create the subjec- subjectivity –attending to the state of one’s tive impression that the appearance is not awareness without construing its contents something separate from one’s mind. As a as separate from the subjectivity – the next means to heighten one’s awareness of subjec- stage of the practice involves techniques tivity, the same types of questions are then that de-emphasize subjectivity itself. The- applied to the phenomenal appearance as oretically, this is accomplished in part by mind (with questions such as, “What color one’s facility at releasing objects. That is, is the mind?” “What shape is the mind?”), because awareness is construed as subjec- which has the effect of pointing out the man- tivity in relation to objects, the practice of ner in which the phenomenal content is acci- releasing objects will also erode subjectivity. dental to the experience. Along with or in But another important aspect of this stage lieu of such strategies, a deliberate perturba- of practice is not to grasp onto subjectivity tion – such as a sudden shout – may be intro- itself as an object. That is, as one is attempt- duced into the meditation so that the effects ing to abide in a state that is aware and yet on subjectivity will be especially salient. not focused on an object, one may still have The move to an emphasis on subjectivity a sense of subjectivity that is caught up in an is further encouraged by dropping any delib- identity that extends beyond the particular erate focus on an object. As a sensory con- moment – as such, that sense of an identity is tent or mental event occurs, one observes considered an accidental feature of the state it (sometimes along with the momentary because it changes over time. use of a discursive strategy), and then one One of the many remedies employed here releases any focus on it. This is similar to the is the repeated (and somewhat paradoxical) Vipassana¯ practice discussed above, except instruction not to make an effort to meditate. that after releasing the content or event one In other words, for the meditator a persistent does not return to any object. Instead, one way that the sense of “I” manifests would releases the mind into its “natural state” (rang be in the form of a thought, such as, “I am babs), which one understands to be the state meditating.” Such a thought involves con- reﬂecting only the invariant nature of conceptual and linguistic structures that consciousness and not the accidental properties nect to a sense of “I” located in the past and of subject and object. the future. And because that way of locat- One is also repeatedly reminded by one’s ing subjectivity – essentially as a narrative instructor that “grasping” (’dzin pa) – taking agent – changes from one cognitive context the mental content as an object – is to be to the next, it is a type of subjectivity that avoided. Here, the gross symptoms of grasp- is thought to obscure the invariant feature ing include indications that one has begun of consciousness. According to most tradi- to focus on or examine the content or event tional accounts, it is extremely difﬁcult to and then elaborate upon it – in a phrasing de-emphasize subjectivity to this degree. As P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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a result, most beginner and mid-range med- continue to experience phenomena with- itators engaged in the cultivation of open out objectifying them and, ideally, with- presence are likely to be actually meditating out having a sense of an agentive or nar- at the level below this stage; that is, the stage rative subjectivity. The state thus seems to at which subjectivity is still emphasized. cultivate a type of ipseity or bare aware- Through the above techniques – along ness. After a session, for advanced medi- with other methods that involve visualiza- tators the objects of perception will phe- tions and breathing exercises – advanced nomenally appear to be less fixed and more meditators are thought to eventually induce like appearances in a dream or a mirage a particular phenomenal experience: The for at least some period afterward. And as experience’s content does not appear as an one advances further, the state between ses- object over against a subject, and the expe- sions begins to seem more like Open Pres- rience also does not involve a sense of sub- ence itself. The relevant longer-term traits jectivity that is articulated by conceptual that are expected to arise from cultivating or linguistic structures, even if those struc- Open Presence include most prominently tures are only implicit. It is worth reiterat- a facility to regulate one’s emotions, such ing, however, that in de-emphasizing both that one is disturbed less easily by emotional object and subject, the aim of the practice is states. The mind is also said to be more not to become withdrawn from experiences, sensitive and flexible, and the cultivation whether perceptual or mental. Instead, the of other positive states and traits is there- aim is for experiences to continue to occur fore greatly facilitated. All three of our main even though the state de-emphasizes the traditional sources (Karma Chagme,´ 2000; particularity of the object and subject. It is Thrangu & Johnson, 2004; Wangchug Dorje,´ in this way that, according to Chag-zôg theo- 1989) make it clear that these and other rists, one will become aware of the invariant indications are thought to be observable in feature of all states of consciousness. behavior, because it is through observing and Finally, at the highest level of practice, interviewing students that the meditation what we have described as a de-emphasis master is able to guide them in this difficult of both object and subject moves, at least practice. theoretically, to a point where no elements of objectivity or subjectivity – whether in non-referential compassion the form of conceptual structures, categories (mıg-mˆ e´ nying-je´) of time and space, or some other feature – Unlike practices oriented toward gener- remain in the experience. At this point, the ating Focused Awareness or Open Pres- invariant feature of cognition is said to be ence, the practice of Non-Referential realized fully by the meditator, and this is the Compassion aims to produce a specific full-blown state of Open Presence. It seems emotional state; namely, an intense feeling that because this state is extremely advanced of lovingkindness.5 The state is necessar- in each generation of practitioners the Chag- ily other-centered, but it is non-referential zôg traditions recognize only a small number (dmigs med) in that it does not have any spe- of practitioners as having truly reached this cific object or focus (dmigs pa), such as a level of practice. specific person or group of persons. Thus, In terms of the effects of the practice, in effect this meditation has two aspects: one ability developed through cultivating the cultivation of compassion and the cul- Open Presence is the stability of the state – tivation of objectless awareness (i.e., Open that is, one is not easily perturbed out of the Presence). Hence, this practice may be con- state. The difference, however, is that unlike sidered a kind of variation on Open Pres- in Focused Attention, in Open Presence ence, but it also differs somewhat from Open the stability is not constituted by the fact Presence. That is, except for the earliest that other phenomena do not pull one stages of the practice, in Open Presence away from the object on which one focuses. the meditator does not usually require any Instead, stability consists of one’s ability to particular mental content or event as the P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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context for the cultivation of Open Presence. a person toward whom one feels indiffer- But in the cultivation of Non-Referential ence. With a visualization of these persons Compassion, one does require a particular in place, one then employs discursive strate- mental event – the emotion of compassion – gies – such as the argument that all beings are that forms the context for the cultivation equal in wanting to be happy and wishing to of the objectless awareness that is Open avoid suffering – that are designed to elimi- Presence. nate one’s biases toward these persons. In the The two aspects of Non-Referential Sevenfold Causal Instructions, one is then Compassion – compassion and Open Pres- encouraged not only to see all beings as equal ence – must occur together for the med- but also to take one’s mother as paradig- itation to be successful (Wangchug Dorje,´ matic of all beings. Another set of discur- 1989), but although precise descriptions of sive contemplations – sometimes including this practice are not readily available, it specific visualizations – are then used to disappears that for many practitioners this prac- place one’s preferential treatment of oneself tice requires a sequence within the session. over others. One contemplates, for example, In some cases, a meditator may first cultivate how despicable one would be to prefer one’s Open Presence and then cultivate compas- own happiness over the well-being of one’s sion while retaining the state of Open Pres- mother; here, the practitioner might recall ence to the greatest degree possible. After a memorized aphorism or the admonitions compassion has been evoked, the meditator of his or her teacher. Finally, by recalling may then emphasize Open Presence once or visualizing the intense suffering experi- again, because the techniques for cultivat- enced by others – i.e., “all sentient beings ing compassion may have led the medita- who are as if one’s mother” (ma sems can tor to stray from an objectless state. In other thams cad) – one becomes motivated empa- cases, a meditator may begin by first evok- thetically to eliminate that suffering. Toward ing compassion, and then, while the mind the endpoint of this process one experiences is suffused with compassion, the meditator a visceral, emotional reaction that is said will cultivate Open Presence. to involve especially a feeling of opening at The sequentiality of the practice, which the center of the chest, sometimes accom- does not apply to the most advanced prac- panied by horripilation and the welling of titioners, stems largely from the methods tears in the eyes. This state involves both love that are initially used to evoke a compas- (matr¯ı) – the aspiration that other beings be sionate mental state. These methods often happy – and compassion (karun. a)¯ – the aspi- combine multiple techniques, most espe- ration that other beings be free of suffer- cially a discursive strategy (usually the steps ing. At this point the state might involve a of a memorized argument), a set of visu- degree of sentimentality, and the final phase alizations, and sometimes a litany or other of developing compassion is meant to go recitation. In all the Tibetan traditions, three beyond that state to one that is both more such meditations are widely practiced: the stable and also more engaged with aiding “Sevenfold Causal Instructions” (sems bskyed others (Dalai Lama XIV, 1991). rgyu ’bras man ngag bdun), the “Equanimous Most Tibetan practitioners are trained Exchange of Self and Other” (bdag bzhan intensively in this type of contemplation mnyam brjes), and the practice of “Giving for generating compassion. It is evident, and Taking” (gtong len) (Dalai Lama XIV, however, that these techniques for induc- 1991, 1995). ing compassion are not objectless, inas- All three of these practices, which them- much as they involve visualizations, argu- selves may be combined in various ways, typ- ments, aphorisms, litanies, and so on that are ically begin with an evocation of equanimity focused on objects of one kind or another. (btang snyoms, Skt, upeks.a)¯ . Often a visu- Nevertheless, having generated compassion, alization of three persons is used: a beloved the practitioner can then cultivate Open person (most especially one’s mother), a per- Presence from within that state. Indeed, as son for whom one has some enmity, and a phenomenally intense state, compassion P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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is well suited to the early stages of cul- Generating a Description tivating Open Presence, because compassion’s intensity lends itself well to an aware- As the discussion above indicates, even ness of subjectivity and, hence, reflexivity. within Buddhism a large number of distinct And if the emotional state of compassion contemplative practices continue to be prac- can be sustained even while one is cultivat- ticed in living traditions. For this reason, ing Open Presence, the meditator is in the significant changes in meditative style are state of Non-Referential Compassion. As a found even for a basic samatha´ style of med- meditator becomes more adept at cultivat- itation focused on the sensation made by ing compassion through the various tech- the breath. For instance, practitioners from niques mentioned above, the mind becomes the Vipassana¯ or Insight Meditation move- more habituated to the state such that an ment may practice this meditation with the advanced practitioner can induce the state eyes closed so as to de-emphasize the impor- of compassion almost effortlessly. At this tance of the visual modality. In contrast, clos- stage the practice would no longer require ing the eyes is rarely encouraged in the Zen a sequence; that is, compassion can be cul- and Tibetan traditions, in part because it is tivated directly within a state of Open Pres- assumed to induce dullness or drowsiness. ence itself (Wangchug Dorje,´ 1989). The difference of opinion concerning the In general the cultivation of compassion closing of the eyes is illustrative of the dif- is thought to grant the meditator numerous ficulties that researchers face when speci- beneficial effects between sessions, such as fying the exact nature of a meditation to creating a general sense of well-being and be studied. One main problem is that the aiding in counteracting anger or irritation. traditional accounts of these practices move Long-term practitioners of this practice are far beyond the sketches given here; instead, also said to have an effect on others around those accounts are usually highly detailed them, in that other persons nearby may also and extremely complex. Likewise, the ter- feel a greater sense of well-being and happi- minology used to describe the practices ness. Compassion is also thought to provide is sometimes unreliable, either because of benefits when one is in a meditative session ambiguities in the traditions themselves or involving other practices. It is especially use- problems in translation. Practices from dif- ful for counteracting torpor in meditation; ferent traditions may in fact overlap signifi- that is, it is a considered a strong antidote cantly – the overlap between contemporary for dullness, as mentioned earlier. Likewise, Mindfulness practice and Open Presence because compassion is other-centered, it is meditation is one case in point. Finally, sub- considered to develop traits that are essential jects from traditionally Buddhist cultures for the successful cultivation of Open Pres- sometimes are reluctant to depart from tex- ence. That is, in developing Open Presence tual descriptions of meditative practices. To one must eliminate the mind’s “grasping” do so would require a practitioner to assert directed toward objects and also toward sub- some authoritative experience as a medita- jectivity itself. Grasping, moreover, is rooted tor, and it is usually thought to be inappro- in a persistent trait within the mind that priate to claim that degree of accomplish- absolutizes the standpoint of the subject. By ment in meditation. persistently orienting the meditator toward Researchers may also encounter problems others, compassion lessens this fixation on when attempting to assess the degree of self and makes it possible for grasping to training and practice over the life of a par- be eliminated through the practice of Open ticular practitioner. One of the main diffi- Presence. In this way, the cultivation of com- culties is that, traditionally, contemplative passion is thought to train the mind in a way practice involves many varieties of medita- that is essential to the success of some prac- tion, each of which mutually influence each tices (Dalai Lama XIV, 1991, 1995; Karma other and differentially affect the mind. The Chagme,´ 2000; Thrangu & Johnson, 2004; quantification of the total hours of medita- Wangchug Dorje,´ 1989). tion throughout a practitioner’s life is thus P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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not straightforward and will require further through the senses, or is it imagined methodological development. in the mind through visualization or In any case, before tackling the prob- another technique? r lem of quantification, an important task for If the meditation does not include an any researcher is generating a precise and object, then does one direct one’s atten- concrete account of the practices in which tion to something else? meditating subjects claim to be engaged. The 3. Concerning meditative techniques, one may best way to proceed is probably to develop ask the following: r a list of questions that can be used to Is the practice done with the eyes help prompt descriptions from practitioners opened or closed? r without getting caught either in traditional Does the practice employ any discur- categories or issues of cultural translation. To sive strategies, such as recitations, mem- assist researchers in this task, we close this orized descriptions, or arguments that section on Buddhist meditation with a prac- one reviews? r tical series of sample questions that would Does the practice use breath mani- aid both the meditator and researcher in pulation? r defining more clearly the relevant facets of Does the meditation involve focus- the practice to be studied. The questions ing on different parts of the body by address five overall issues: (1) the relative means of a visualization or some other degree of stability and clarity appropriate to technique? r the practice; (2) the “intentional modality” Does the practice require a specific pos- (i.e., whether the meditation has an object); ture or set of physical exercises? 3 ( ) the techniques, such as breath manipu- 4. Concerning expected effects during medita- 4 lation, that are employed; ( ) the expected tion, one may ask the following: r effects of the practice during meditation; Is the meditation expected to pro- 5 and ( ) the expected effects after a session. duce any physical sensations or Although based especially on the practice mental events, either constantly or and theory of meditation found in Tibetan intermittently? r Buddhism, questions of this type are likely Does one expect the meditation to to be useful when examining other contem- produce subjectively noticeable alter- plative traditions. ations in cognition, either constantly or 1. Concerning stability and clarity, one may intermittently? One example would be ask the following: the impression that one’s perceptions r In view of the practitioner’s level, seem to be like the appearances in a should the meditation favor stability, dream. r clarity, or a balance? Is the meditation expected to cause b What are the indications that stability any emotions, either constantly or needs adjustment? intermittently? b What are the indications that clarity 5. Concerning expected effects after medita- needs adjustment? tion, one may ask the following: r 2. Concerning intentional modality, one may Does one expect the meditation to alter ask the following: one’s cognitions? One example would r If the meditation includes an object, be the impression that one’s percep- then, tions are more vivid. b r Is there one object or many objects in Does one expect the meditation to alter the meditation? one’s behavior? One example would be b For each object, is the object dynamic a tendency to sleep less. r or static? Does one expect the meditation to alter b If the object includes or consists of one’s emotions? One example would be a visual form, a sound, or a sen- the tendency to recover more quickly sation, then is the object perceived from emotional disturbances. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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By adapting or adding to this list of ques- pass either meditative states or traits indu- tions for the particular practice in question, ced by meditation. Meditative states refer meditators and researchers may be able to to the transient alterations of experience collaborate more readily so as to describe in voluntarily cultivated by a given medita- a straightforward way the major features of tion practice (i.e., bodily awareness, relax- a practice that are relevant to a particular ation, emotions, and so on). Traits refer neuroscientific research agenda. With such to the lasting changes in these dimen- descriptions in place, the dialogue between sions that persist in the practitioner’s daily meditators and researchers can be far more experience irrespective of being actively precise, and the interaction between neuro- engaged in meditation. science and meditation is therefore likely to 2. Advanced practitioners can robustly be more fruitful. reproduce specific features in experience as cultivated in given meditative practice. This reproducibility makes those features The Intersection of Neuroscience scientifically tractable. and Meditation 3. Advanced practitioners provide more refined first-person descriptions of their This section briefly explores some possi- experiences than na¨ıve subjects. Thus, the ble scientific motivations for the neuroscien- neurophysiological counterpart of these tific examination of meditative practices and first-person accounts can be defined, their possible impact on the brain and body identified, and interpreted more easily by in advanced practitioners. The aim here is to the experimentalist. clarify further the distinguishing features of this approach compared to other empirical We now discuss these claims in relation to strategies described in this handbook. Before three neuroscientific agendas: neuroplastic- we move forward with this discussion, how- ity, the interaction of mind and body, and the ever, two points of clarification need to be possibility of neural counterparts to subjec- made. First, because of the relative paucity tive experience. In the course of this discus- of currently available empirical data in this sion, specific techniques from the Buddhist field, this section remains largely program- tradition serve as illustrations. matic. Second, we discuss some studies that involve novice meditators, but the set of Transforming the Mind and issues examined here are most relevant to Brain Neuroplasticity advanced practitioners of meditation. Nev- ertheless, emphasis on advanced practition- From a neuroscientific perspective, the first ers should not minimize the importance of promising claim made by Buddhist con- studying meditation in less practiced individ- templative traditions is that experience is uals. Indeed, some of us have already done so not a rigid, predetermined, and circum- (see, e.g. Davidson et al., 2003). For progress scribed entity, but rather a flexible and trans- in this general area to advance, we believe formable process. On this view, emotions, that research on practitioners at all levels attention, and introspection are ongoing and should be encouraged, but one must also rec- labile processes that need to be understood ognize that the goals of studying individuals and studied as skills that can be trained, sim- at different levels of accomplishment differ ilar to other human skills like music, math- somewhat. ematics, or sports. This principle is founda- Turning now to the question of advanced tional for Buddhist contemplative practice, practitioners, we begin by noting three fre- because such practices are based upon the quently advanced hypotheses: notion that the mind is malleable in this way. As a result, the methods employed by Bud- 1. Advanced practitioners can generate new dhist contemplative practices resonate with data that would not exist without susta- widely accepted developmental models of ined mental training. These data encom- basic cognitive processes; according to these P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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models, cognitive functions are skills that as a cab driver predicted the size of the critically depend upon learning from envi- posterior hippocampus (Maguire et al., ronmental input (e.g., McClelland & Rogers, 2000). Further work by this group suggests 2003; Saffran, Aslin, & Newport, 1996). This that these differences in hippocampal size basic stance reflects another well-accepted are the results of experience and training and well-documented theory; namely, that as a cab driver and not a consequence of experience changes the brain. Interest in pre-existing differences in hippocampal this feature, known as neuroplasticity, has structure (Maguire et al., 2003). prompted an explosion of research over the Whether similar structural alterations in past decade. different regions of the brain occur also as a As a result of ongoing research on neu- consequence of affective – rather than sen- roplasticity, we now have a detailed under- sorimotor – experience is not definitively standing of many of the molecular and known, but all of the extant work at both system-level changes that are produced by the animal and human levels indicates that specific types of experiential input. For it does. Certainly there are good animal example, neonatal rodents exposed to vary- data to suggest that such changes occur, as ing levels of maternal licking and groom- indicated by the study on neonatal rodents. ing develop very different behavioral pheno- In humans, a variety of research indicates types. Those animals that receive high levels that deleterious conditions, such as chronic of licking and grooming (the rodent equiva- stress, neglect, and abuse, produce func- lent of highly nurturing parenting) develop tional changes in the brain that are likely into more adaptable and relaxed adults. Of subserved by structural alterations (Glaser, great interest is the fact that the brains of the 2000). Likewise, research on depression animals are critically affected by this differ- indicates that patients with mood disorders ential rearing. Indeed, gene expression for exhibit structural differences in several brain the gene that codes for the glucocorticoid regions, including the hippocampus and ter- receptor is actually changed by this experi- ritories with the prefrontal cortex; signif- ence, and the detailed molecular pathways icantly, at least some of these differences by which experience can alter gene expres- are associated strongly with the cumulative sion have now been worked out in this model number of days of depression in the patients’ (Meaney, 2001). This program of research lifetimes (Sheline, 2003). illustrates the profound ways in which neu- These findings raise the possibility that roplasticity can unfold, and it demonstrates training and practices that are specifically that experience-induced alterations in the designed to cultivate positive qualities, such brain can occur all the way down to the level as equanimity and lovingkindness, will pro- of gene expression. duce beneficial alterations in brain function Meaney’s work on alterations in brain and structure. Presumably, these alterations gene expression implies that similar would be most prominent in long-term, experience-induced alterations might occur advanced practioners, but we have already in humans. Currently, however, there are shown that even very brief short-term train- no direct measures of localized neuronal ing (30 minutes) in emotion regulation can gene expression that can be non-invasively produce reliable alterations in brain function obtained in humans. Nevertheless, other (Urry et al., 2003). So too, we have observed research suggests that such changes do that a 2-month course in Mindfulness-Based indeed occur. For instance, the brain of Stress Reduction (MBSR) can produce alter- an expert, such as a chess player, a taxi ations in patterns of prefrontal brain activ- driver, or a musician, is functionally and ity that we have previously found to structurally different from that of a non- accompany positive affect (Davidson et al., expert. London taxi cab drivers have larger 2003). hippocampi than matched controls, and the The findings concerning MBSR may be amount of time the individual has worked especially relevant, because MBSR is likely P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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to provide a large pool of persons for the ine possible anatomical changes induced by study of neuroplasticity and meditation. An meditation. 8-week program that was originally developed in a hospital setting for patients with Mechanisms of Mind-Body Interaction chronic illnesses, MBSR is now applied across an extremely wide range of popu- In addition to the study of neuroplasticity, lations (Kabat-Zinn & Chapman-Waldrop, one of the most potentially fruitful ques- 1988; Kabat-Zinn, Lipworth, & Burney, tions in the study of meditation is the impact 1985). The method, based primarily on of training the mind on peripheral biolog- Buddhist practices, seems to be effective ical processes that are important for phys- for chronic pain, anxiety disorders, gen- ical health and illness. Quite literally, the eral psychological well-being, psoriasis, and question here is whether mental training can recurrent depression (Grossman, Niemann, affect the body in a way that will have a sig- Schmidt, & Walach, 2004). The program nificant impact on physical health. Although seems to work by helping the patient dis- there are many popular claims about the tinguish primary sensory experience (e.g., health benefits of meditation and contem- chronic pain, physical symptoms of anxiety) plative practice, there is relatively little that from the secondary emotional or cognitive is solidly known about this potentially cru- processes created in reaction to the primary cial issue. Even more importantly, there are experience. Individuals are trained to use the preciously few attempts to mechanistically mindfulness practice to elicit the details of link the changes that are occurring in the their experience and to directly perceive the brain with alterations that may be produced unstable and contingent nature of the feel- in peripheral biology. It is beyond the scope ings and sensations that are associated with of this chapter to review the basic research aversion and withdrawal; as a result, indvid- relevant to these questions, but it provides uals are better able to counter any propensity some general guidelines and examples. toward withdrawal and aversion in response It is established that there is bidirectional to physical or psychological pain. communication between the brain and the From a neuroscientific perspective, the periphery and that this communication pro- apparent effectiveness of MBSR practice ceeds along three basic routes: the auto- raises the question of neuroplasticity – that, nomic nervous system, the endocrine sys- is, does it produce alterations in brain func- tem, and the immune system. In each of tion and structure? Recent data indicate these systems, specific pathways and sig- a possible relationship between medita- naling molecules enable this bidirectional tion training and changes in brain structure communication to occur. These structural (Lazar et al., 2005). In this study, corti- characteristics are highly relevant to the cal thickness was assessed using magnetic possibility that meditation may influence resonance imaging. Increased cortical thick- physical health. That is, some conditions ness could be caused by greater arboriza- of peripheral biology may be potentially tion per neuron, increased glial volume, or affected by meditative practices because increased regional vasculature, all of which those conditions – such as an illness – are important for neural function. Corti- are susceptible to modulation by the auto- cal brain regions associated with attention, nomic, endocrine, and/or immune pathways interoceptive, and sensory processing were involved in brain-periphery communication. found to be thicker for a group of mid-range Thus, because there is bidirectional com- practitioners than for matched controls (the munication between the brain and periph- meditator participants had, on average, 40 ery, it is theoretically possible to affect those minutes of daily practice of Insight medita- types of conditions by inducing changes tion for an average of 9 years). We antici- in the brain through meditation. At the pate that research conducted over the next same time, however, other conditions or ill- 2 years by several groups will further exam- nesses may not be influenced in this way by P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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2.35

2.3

2.25

2.2 8–9 Week 8–9 Week Post-Vaccine

2.15 Log Transformed Antibody Rise from 3–5 Week to Week Antibody Rise from 3–5 Transformed Log 2.1 Control Meditation Figure 19.2 . Effect of meditation training on the immune system during a Mindfulness-Based Stress Reduction program (8-week program) with novice practitioners. Means ± SE antibody increase from the 3-to5-week to the 8-to 9-week blood draw in the Meditation and Control groups. The ordinate displays the difference in the log-transformed antibody rise between the 3-to5-week and the 8-to9-week blood draws derived from the hemagglutination inhibition array. (From Davidson et al., 2003.)

meditation because the peripheral biological body response to the influenza vaccine. We processes in question cannot be affected by found that individuals with high levels of any pathway involved with brain-periphery left prefrontal activation, a pattern that we communication. have previously found to predict more pos- With this in mind, the strategy that we itive dispositional mood, had higher levels have adopted in some of our work is to of antibody titers in response to the vac- examine a proxy measure that we know can cine (Rosenkranz et al., 2003). The spe- be modulated by central nervous changes cific question of whether mental training and that is health-relevant. In a seminal could improve the immune response was study, Kiecolt-Glaser, Glaser, Gravenstein, addressed in our study of MBSR (David- Malarkey, and Sheridan (1996) reported son et al., 2003; Figure 19.2). In this study, that caregivers of dementia patients had an individuals who had been randomly assigned impaired response to influenza vaccine com- to an MBSR group were compared to a pared with a matched control group. Several wait-list control group. Subjects were tested groups have now independently replicated just after the MBSR group had completed this basic finding and have examined some their 8-week training. We found that the of the details regarding the mechanism by meditators exhibited a significantly greater which stress might impair humoral immu- antibody response to the influenza vaccine. nity (e.g., Miller et al., 2004). Of most importance in this study was an In our group, we have investigated analysis we conducted that examined rela- whether individual differences in patterns of tions between brain and immune function prefrontal brain activity that we have pre- changes with meditation. We found that for viously found to be associated with affec- the individuals assigned to the meditation tive style (i.e., individual differences in pro- group, those who showed the greatest shift files of affective reactivity and regulation) toward left-sided activation also exhibited are also associated with differences in anti- the largest increase in antibody titers to the P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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CONTROL MEDITATION RECOVERY 36 CALF NAVEL LUMBAR 34 TOE 32 STERNUM FOREARM 30

° 28 26 FINGER 24 100 HEART RATE Temperature ( Temperature 80 − 22 (beats min 1) 20 60 AIR 18

010203040102030

CONTROL MEDITATION 0 RECOVERY Time(min) Figure 19.3. Effect of Tummo meditation of the regulation of body temperature. Skin and air temperature and heart rate changes before, during, and after the meditation of long-term practitioner L.T. (adapted from Benson et al., 1982).

vaccine. These findings suggest some associ- practices can affect the body in a way that ation between the magnitude of neural and improves health. immune changes. A variety of other findings in the litera- Using First-Person Expertise to Identify ture suggest that autonomic changes occur the Neural Counterpart of during specific types of meditation. As Subjective Experience noted in the first part of this chapter, the Tibetan Tummo practice has as its byprod- As discussed in the first section of this chap- uct the production of heat. Benson and his ter, various meditative practices induce a colleagues reported on three practitioners wide variety of altered states of conscious- and found that, by using this practice, they ness. It is thus frequently claimed that the were indeed able to voluntarily increase tem- study of meditation will contribute to our perature in their toes and fingers by as much general understanding of the neural basis of as 8◦C (Figure 19.3; Benson et al., 1982). consciousness. Here we aim to move beyond Takahashi et al. in a study of Zen medita- this general claim and illustrate how specific tion in a fairly large sample (N = 20) found Buddhist practices might provide research changes in heart rate variability (reflect- opportunities to glean new insights about ing parasympathetic nervous system activ- some of the brain mechanisms contributing ity) that were associated with changes in to consciousness. More precisely, we discuss specific EEG frequencies (Takahashi et al., how the collaboration with long-term Bud- 2005). In future studies, the combination of dhist practitioners is of great interest in the both brain and peripheral measures will be study of (1) the physical substrate of sub- important in helping understand the mecha- jectivity or the self, (2) the physical prin- nisms by which such peripheral changes may ciples underlying the emergence of coher- be occurring. This type of data will be espe- ent conscious states from unconscious brain cially useful as research moves forward on processes, and (3) the functional role of the the practical question of whether meditative spontaneous brain baseline. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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studying the substrate explained as involving a reflexive awareness of subjectivity of one’s lived body or embodied subjectiv- One of the useful points of intersection ity correlative to the experience of the object between Buddhist contemplative practice (Mearleau-Ponty, 1962; Wider, 1997). It is, in and the neuroscience of consciousness is the short, another way of speaking about ipseity. emphasis on understanding the nature of the If the above model is correct, then in self. A comparison between Buddhist and giving an account of consciousness, neuro- neuroscientific models of the self is beyond science needs to explain both “how the brain the scope of this chapter, but it is impor- engenders the mental patterns we experi- tant to note that both traditions distinguish ence as the images of an object” and “how, between a minimal subjective sense of “I- in parallel . . . the brain also creates a sense ness” in experience, or ipseity, and a narrative of self in the act of knowing . . . ” In other or autobiographical self. Ipseity is the mini- words, to give an account of consciousness, mal subjective sense of I-ness in experience, neuroscience must show how it is that one and as such, it is constitutive of a minimal or has a “sense of me” by demonstrating “how core self. By contrast, a narrative or autobio- we sense that the images in our minds are graphical self (Legrand, 2005) encompasses shaped in our particular perspective and categorical or moral judgment, emotions, belong to our individual organism” (Dama- anticipation of the future, and recollections sio, 1999,pp.136–137). As a number of of the past. This explicit sense of narra- cognitive scientists have emphasized, this tive or autobiographical self is often char- primitive self-consciousness might be fun- acterized as occurring in correlation with an damentally linked to bodily processes of life explicit content, or object, of experience. It regulation (Damasio, 1999; Panksepp, 1988). also appears to be dependent in some fash- This approach to the question of con- ion on ipseity, inasmuch as the narrative self sciousness suggests a research strategy that is in part based upon that minimal subjective might be aided by the use of experienced sense of I-ness. meditators. That is, to understand conscious- The notion of ipseity is further explained ness, it is presumably best to begin by exam- through Western phenomenological theory, ining it in its simplest form. And on this the- according to which one can speak of experi- ory, the simplest form of a conscious state is ence in terms of both transitive and intran- reducible to ipseity, which is required for or sitive modes of consciousness. Any experi- is prior to the narrative self. One experimen- ence “intends” (i.e., refers to) its intentional tal strategy would be to involve long-term object; this is its transitive aspect. At the practitioners of a practice such as Open Pres- same time, the experience is also reflexive- ence that allegedly induces a state in which ly manifest to itself, and this is its intransi- ipseity is emphasized and the narrative self tive aspect. On this theory, the intransitive is lessened or eliminated. By examining such aspect of experience is a form of self- practices, one may be able to find neural cor- consciousness that is primitive inasmuch as relates of a bare subjectivity, which in turn it (1) does not require any subsequent act may yield some insight into the neural cor- of reflection or introspection, but occurs relates of the most basic type of coherent simultaneously with awareness of the object; states that we call consciousness. (2) does not consist of forming a belief or making a judgment; and (3) is passive in studying the substrate the sense of being spontaneous and involun- of consciousness tary (Zahavi & Parnas, 1998). For instance, Empirical evidence clearly indicates that when one consciously sees an object, one only a selective set of neurons in the brain is also at the same time aware of one’s participates in any given moment of con- seeing; similarly, when one visualizes a men- sciousness. In fact many emotional, motor, tal image, one is also aware of one’s visualiz- perceptual, and semantic processes occur ing. This tacit self-awareness has often been unconsciously. These unconscious processes P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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are usually circumscribed brain activities in ally specialized brain regions. A common local and specialized brain areas (Dehaene theoretical proposal is that each moment of & Naccache, 2001). This result suggests that, conscious awareness involves the transient when a stimulus is phenomenally reportable selection of a distributed neural popula- from the standpoint of experience, it is tion that is both integrated or coherent, the result of translocal, large-scale mecha- and differentiated or flexible, and whose nisms that somehow integrate local func- members are connected by reciprocal and tions and processes. In other words, it has transient dynamic links. As we show in been hypothesized that the neural activ- the next section, neural synchronization ity crucial for consciousness most probably and de-synchronization between oscillating involves the transient and continual orches- neural populations at multiple frequency tration of scattered mosaics of functionally bands are popular indicators of this large- specialized brain regions, rather than any sin- scale integration (Engel, Fries, & Singer, gle, highly localized brain process or struc- 2001; Varela, et al. 2001). For instance, dur- ture (Dehaene & Naccache, 2001; Llinas, ing the binocular rivalry discussed above Ribary, Contreras, & Pedroarena, 1998;W. the alternation of perceptual dominance Singer, 2001; Tononi & Edelman, 1998). correlates with different ongoing patterns The issue at stake here can be illus- of distributed synchronous brain patterns trated by the example of binocular rivalry. (Cosmelli et al., 2004; Srinivasan, Russell, When the right eye and the left eye are pre- Edelman, & Tononi, 1999). sented with competing, dissimilar images, Thus it is hypothesized that large-scale the observer does not experience a stable integrative mechanisms play a role in con- superimposed percept of the images pre- scious processes. However, these large-scale sented to the two eyes, but instead per- brain processes typically display endoge- ceives an ongoing alternation between the nous, self-organizing behaviors that cannot images seen by each eye every couple of sec- be controlled fully by the experimenter and onds. When one percept is consciously per- are highly variable both from trial to trial and ceived, the other remains unconscious. Yet, across subjects. Linking these brain patterns even if a stimulus is not reportable, there to the experiential domain is notoriously dif- is evidence it is still processed by the brain ficult in part because the first-person reports in various ways. Activity in the amygdala, are readily inaccurate or biased (Nisbett & which is known to increase during the pre- Wilson, 1977). The problem, in a nutshell, sentation of facial expressions of fear and is that the experimenter is led to treat as anger, is still detectable even when the emo- noise the vast majority of the large-scale tional face is suppressed because of binoc- brain activity, as he or she can neither inter- ular rivalry (Williams, Morris, McGlone, pret it nor control it. Abbott, & Mattingley, 2004). It is in this context that meditation Binocular rivalry suggests that local neu- becomes relevant. We hypothesize that ral processes – such as those involved in the long-term practitioners of meditation can processing of visual stimuli – are not in them- generate more stable and reproducible men- selves sufficient to account for conscious- tal states than untrained subjects and that ness. In other words, the neural process they can also describe these states more occurs, but may or may not be consciously accurately than na¨ıve subjects. The prac- experienced. Some other process or mech- titioners’ introspective skills could provide anism must be involved. It is in response a way for experimenters to better control, to this type of issue that contemporary identify, and interpret the large-scale inte- researchers (Llinas et al., 1998; Singer, 2001; grative processes in relation to the subjective Tononi & Edelman, 1998) have hypothe- experience. sized some kind of integrative mechanisms This “neurophenomenology” approach or processes that, although transient, are (Varela, 1996) was tested in the context of able to orchestrate or coordinate function- a visual protocol with na¨ıve subjects. On P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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the day of the experiment, participants were modification in rivalry rate, in contrast with first trained during a practice session to be Focused Attention meditation, which led to aware of subtle fluctuations from trial to extreme increases in perceptual dominance trial in their cognitive context as defined by durations that were reported by 50%of their attentive state, spontaneous state pro- monks after a period of single-pointed med- cesses, and the strategy used to carry out the itation. The monks reported additional sta- task. During the visual task, their electrical bilization of the visual switching when they brain activity and their own report about did the visual task during Focused Attention their cognitive context were recorded. Tri- meditation. als were clustered according to the acquired In sum, the capacity of long-term prac- first-person data, and separate, dynamical titioners to examine, modulate, and report analyses were conducted for each cluster. their experience might provide a valuable Characteristic patterns of synchrony in the heuristic to study large-scale synchronous frontal electrodes were found for each clus- brain activity underlying conscious activity ter, depending in particular on the sta- in the brain. bility of attention and the preparation to do the task (Lutz, Lachaux, Martinerie, & meditation and physiological Varela, 2002). baselines As discussed in the report by Lutz and A central goal of the practice of meditation is Thompson (2003), the collaboration with to transform the baseline state of experience long-term practitioners will be particularly and to obliterate the distinction between relevant to the further extension of this the meditative state and the post-meditative research strategy. Let us return again to the state. The practice of Open Presence, for binocular rivalry paradigm. The perceptual instance, cultivates increased awareness of selection in rivalry is not completely under a more subtle baseline (i.e., ipseity) during the control of attention, but can be mod- which the sense of an autobiographical or ulated by selective attention (Ooi & He, narrative self is de-emphasized. Long-term 1999). Evidence suggests in particular that training in Compassion meditation is said the frequencies of the perceptual switch to weaken egocentric traits and change the can be controlled voluntarily (Lack, 1978). emotional baseline. Practitioners of Mind- It is possible that long-term practitioners fulness/Awareness meditation aim to expe- of Focused Attention meditation can gain rience the present nowness, and this type a more thorough control of the dynamic of meditation affects the “attentional base- of perceptual switch than na¨ıve subjects line” by lessening distractions or daydream- and that they can also refine their descrip- like thoughts. In this way, meditative prac- tions of the spontaneous flow of perceptual tices are generally designed to cultivate dominance beyond the mere categories of specific qualities or features of experience being conscious of one or another percept, that endure through time relatively indepen- thereby leading possibly to new brain cor- dent of ongoing changes in somatosensory or relates. Carter et al. (2005) recently pro- external events. These qualities are thought vided behavioral evidence that long-term to gradually evolve into lasting traits. practitioners can indeed change the rivalry From an empirical standpoint, one way to rate during meditation. They reported differ- conceptualize these various meditative traits ential effects on visual switching accompa- is to view them as developmental changes nying rivalry during Non-Referential Com- in physiological baselines in the organism. passion meditation and Focused Attention Finding ways of systematically characteriz- meditation (see the earlier discussion on ing these baselines before, during, and after meditative states in Tibetan Buddhism) mental training is thus crucial for the empir- among 23 Tibetan Buddhist monks vary- ical examination of the long-term impact of ing in experience from 5 to 54 years of meditation. A systematic characterization of training. Compassion meditation led to no baselines in the context of meditation is also P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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an important methodological issue because ulate and maintain the organization of the an essential aspect of experimental research system even amid environmental perturba- is the identification and control of a base- tions. It is in this sense that the notion of a line against which the condition of inter- baseline is related to the ongoing identity of est can be contrasted. Underestimating this an organism. And given the sensitivity that issue is a potential source of confusion when most contemplative traditions show to this studying meditation practitioners, particu- type of issue, the search for baseline changes larly long-term practitioners, because the throughout the continuum of mental train- contrast between the initial baseline and the ing is a general strategy that can potentially meditative state might be biased by a base- be applied to clarify mind-brain-body inter- line difference between groups (i.e., novices actions at many explanatory levels, includ- versus adepts). ing brain chemical, metabolic, or electrical When conceptualizing the notion of a activity; the immune system; the cardiovas- baseline, perhaps the most useful approach cular system; and the hormonal system. is to consider a baseline in terms of the This idea can be illustrated with the case capacity for living systems to maintain their of metabolic and electrical brain baselines. identity despite the fluctuations that affect Investigation of the metabolic brain baseline them. Indeed, for many theorists this abil- began following the finding that in an awake ity is one of the most fundamental biologi- resting state, the brain consumes about 20% cal roots of individuality, if not subjectivity of the total oxygen used by the body, despite itself (Maturana & Varela, 1980). This basic the fact that it represents only 2%ofthe notion of homeostatic identity is the intu- total body weight (Clark & Sokoloff, 1999). ition that underlies the concept of a baseline This finding raises the question of the func- in various domains. In the context of medita- tional significance of this ongoing consump- tion, the notion of a baseline is clearly mean- tion of energy by the brain. Interestingly, ingful in relation to “raising the baseline” by brain imaging techniques that permit an developing traits that persist outside of any examination of baseline levels of brain activ- meditative state. In the scientific context, ity have suggested that this global activa- the concept of a baseline plays an impor- tion at rest is not homogeneously localized tant role in characterizing a broad variety of in the brain. There are a consistent set of biological phenomena. Similarly, in psychol- brain areas active at rest with eyes closed, as ogy a baseline state is defined as a resting well as during visual fixation and the passive state by comparison to a task-specific state viewing of simple visual stimuli. The role (say the task of remembering a succession of these activated areas is revealed from the of numbers). In an even broader, ecological attenuation of their activity during the per- context, psychologists attempt also to iden- formance of various goal-directed actions. tify regularities or traits in the average ongo- Because the activity in these areas is asso- ing states of an individual (e.g., mood and ciated with the baseline activity of the brain personality). Areas of biology that study liv- in these passive conditions, Raichle and col- ing processes at a systemic level – such as league have suggested that they are function- the level of the cell, the organism, or the ally active, although they are not “activated” immune system – also use the notion of the (Gusnard & Raichle, 2001). In contrast to baseline to convey the idea that something the transient nature of typical activations, remains constant in the system through time. the presence of this functional activity in the Such features would include, for example, baseline implies the presence of sustained the electrical charges of the neuron, the glu- information processing. cose level in the blood system, and body Our current understanding of the func- temperature. It is important to note that, tional role of these tonically active networks in all these contexts, the functional invari- is still limited. Evidence from brain imaging ance of a given baseline provides information indicates that the posterior part of this toni- about the homeostatic mechanisms that reg- cally activated network (posterior cingulate P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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cortex, precuneus, and some lateral poste- Neuroelectric and Neuroimaging rior cortices) is important for the continuous Correlates of Meditation gathering of information about the world around and possibly within us, whereas the The search for the physiological correlates anterior part (ventro- and dorsoventral pre- of meditation has been centered essentially frontal cortices) is important for the ongo- on three groups: Yogis and students of Yoga ing association among sensory, emotional, in India, adherents of Transcendental Med- and cognitive processes that participate in itation (TM; Becker & Shapiro, 1981)in spontaneous self-referential or introspec- the United States, and practitioners of Zen tively oriented mental activity (Gusnard & and Tibetan Buddhism in Japan, the United Raichle, 2001). One can speculate that, given States, and South Asia (India, Nepal). His- the nature of many meditations, these brain torically, the first studies took place in Asia areas activated in the resting brain will be in the 1950s with advanced yogic practi- functionally affected by long-term medita- tioners in India (Das & Gastaut, 1955) and tive practices. with long-term Zen practitioners in Japan Similarly, the awake, resting brain is (Kasamatsu & Hirai, 1966). Since the 1970s, associated with a well-defined neuroelec- meditation research has been done almost tric oscillatory baseline different from the exclusively in the United States on prac- one during sleep, anesthesia, or active titioners of TM (Becker & Shapiro, 1981); mental activity. Changes in this baseline over 500 studies have been conducted to index are implicated in developmental pro- date. Compared to the degree and sophis- cesses in children, aging, cognitive IQ, and tication of the training of practitioners in mental disorders (Klimesch, 1999). Along the early studies conducted in Asia, TM these same lines, we found a group differ- research relied mainly on the experience ence in the initial premeditation baseline of relatively novice Western practitioners between long-term Buddhist practitioners using mostly a single standard relaxation and novices, suggesting some impact of long- technique. term mental training (Lutz, Greischar, Rawl- Since the late 1990s, we have witnessed a ings, Ricard, & Davidson, 2004). The num- renewed interest in research on meditation. ber of hours of formal meditation during the Various researchers have begun the explo- lifetime of long-term Buddhist practition- ration of a broad range of meditative prac- ers correlates with some oscillatory proper- tices inspired by various traditions – such ties of the brain electrical baselines. Further- as Zen, Tibetan Buddhism, Yoga, and Qi- more, we showed that the post-meditation gong – involving novices, patients, or long- baseline was affected by the meditation ses- term practitioners. Academic research insti- sion, and this suggests a short-term effect tutions are starting to express an interest of meditation on the EEG baseline (Figure in this area as epitomized by the Mind 19.4). In any case, this question of a neuro- and Life meetings at MIT in 2003 and a electric baseline and its relation to mental meeting co-sponsored by the John Hop- training is a fruitful one, and it is currently kins School of Medicine and the George- being investigated, as is discussed in more town School of Medicine in November 2005 detail in the next section. between the Dalai Lama, along with other To summarize, our functional under- Buddhist scholars, and neuroscientists (Bari- standing of the brain and body baselines naga, 2003). remains largely incomplete, and given the This new, broad interest has been fostered importance played by some notion of a base- by several factors. First, the neurobiology of line in most meditative traditions, it is likely consciousness and cognitive, affective, and that our understanding will be significantly social neuroscience have become central and advanced by understanding those meditative accepted areas of research in neurosciences practices that, above all else, aim to trans- over the last two decades, which lends form the “baseline of the mind.” legitimacy to the research on meditation. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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a % % b % 100 100 Controls * 80 * Practitioners * 45 45 * * 40 ** * ** * 0 0 0 12345678910 12345678 IB OB MS Controls Practitioners Figure 19.4. Relative EEG gamma power during non-referential compassion meditation in a group of novices and a group of long-term Buddhist practitioners. a–b. Intra-individual analysis on the ratio of gamma (25–42 Hz) to slow oscillations (4–13 Hz) averaged through all electrodes. a. The abscissa represents the subject numbers, the ordinate represents the difference in the mean ratio between the initial state and meditative state, and the black and red stars indicate that this increase is greater than two and three times, respectively, the baseline standard deviation. b. Interaction between the subject and the state factors for this ratio (ANOVA, F(2,48) = 3.5, p <.05). IB (initial baseline), OB (ongoing baseline) and MS (Fischer, 1971 #68). The relative gamma increase during meditation is higher in the post-meditation session. In the initial baseline, the relative gamma is already higher for the practitioners (p <.02) than the controls and correlates with the length of the long-term practitioners’ meditation training through life (adapted from Lutz et al. 2004).

Second, because meditative practices, such oscillatory neural synchrony and as Yoga or Mindfulness-Based Stress Reduc- consciousness tion (MBSR), are now used routinely in the In 1929, Hans Berger recorded for the first medical environment, clinicians recognize time a human brain’s EEG and reported the need to validate its impact on the brain the presence of several brain rhythms in and the body. these signals (Berger, 1929). Since Berger’s first observation, the various ongoing brain oscillations have been used successfully to characterize mental states, such as sleep, the Neuroelectric Correlates of waking state, or vigilance, and mental Meditative States pathologies, such as epilepsy. Sensory evo- Since 1950s, the electrophysiological mea- ked potentials (EEG signals triggered by an sure of brain or autonomic system has been external stimulation) or the Bereitschaftpo- the most popular imaging tool with which tential (a “readiness EEG potential” that can to study meditation. be recorded over motor areas up to 1 s before Electroencephalography (EEG: Cooper the execution of a movement) have demon- et al., 2003) is a non-invasive technique strated that such mental factors as sensation, that measures the electrical potentials on the attention, intellectual activity, and the plan- scalp. EEG has an excellent temporal reso- ning of movement all have distinctive elec- lution in the millisecond range that allows trical correlates at the surface of the skull the exploration of the fine temporal dynamic (Zeman, 2001). of neural processes. Below we discuss some Even though EEG results may be also basic findings about the nature and function contaminated by muscle activity, EEG oscil- of brain oscillatory processes as measured lations are believed to reflect mostly the by electrophysiology, present some common post-synaptic activity of neurons, in partic- theoretical assumptions about the neurody- ular from the neocortex. More precisely, namic basis of consciousness, and review the when a large population of neurons recorded neuroelectric correlates of various medita- by a single electrode transiently oscillates at tive styles. the same frequency with a common phase, P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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their local electric fields add up to produce a nections with conduction delays of 4 to 6 burst of oscillatory power in the signal reach- ms. Most electrophysiological studies in ani- ing the electrode (Nunez, Wingeier, & Sil- mals have dealt with short-range synchronies berstein, 2001). The amplitude, or power, or synchronies between adjacent areas cor- of these EEG oscillations thus provides a responding to a single sensory modality. coarse way to quantify the synchronization These local synchronies have usually been of a large population of oscillating neurons interpreted as a mechanism of perceptual below an electrode. binding – the selection and integration of Oscillatory neural synchrony is a funda- perceptual features in a given sensory modal- mental mechanism for implementing coor- ity (e.g., visual Gestalt features). dinated communication among spatially dis- Large-scale integration concerns neural tributed neurons. Synchrony occurs in the assemblies that are farther apart in the brain at multiple spatial and temporal scales brain and are connected through polysy- in local, regional, and long-range neural naptic pathways with transmission delays networks. At the cellular level, oscillatory longer than 8 to 10 ms (Schnitzler & Gross, synchrony, or phase synchrony, refers to the 2005; Varela et al., 2001). In this case, syn- mechanism by which a population of oscil- chrony cannot be based on the local cellular lating neurons fires their action potentials architecture, but must instead reside in dis- in temporal synchrony with a precision in tant connections (cortico-cortical fibers or the millisecond range. At the population thalamocortical reciprocal pathways). These level, neuronal synchrony is best analyzed pathways correspond to the large-scale con- by looking at the common average oscil- nections that link different levels of the latory neural activity among the popula- network in different brain regions to the tion. This oscillatory activity can be mea- same assembly. The underlying mechanism sured either from the local field potentials of long-range synchrony is still poorly under- (the summated dendritic current of local stood (for a model see Bibbig, Traub, & Whit- neural groups) or from the macroscale of tington, 2002). Long-range synchronization scalp recordings in EEG (Becker & Shapiro, is hypothesized to be a mechanism for the 1981) and magnetoencephalography (MEG); transient formation of a coherent macro- Srinivasan et al., 1999). The emergence of assembly that selects and binds multimodal synchrony in a neural population depends networks, such as assemblies between occip- on the intrinsic rhythmic properties of indi- ital and frontal lobes, or across hemispheres, vidual neurons, on the properties of the net- which are separated by dozens of millisec- work (Llinas et al., 1998), and on the inputs onds in transmission time. The phenomenon delivered to the network. As a general princi- of large-range synchrony has received con- ple, synchrony has been proposed as a mech- siderable attention in neuroscience because anism to “tag” the spatially distributed neu- it could provide new insights about the rons that participate in the same process emergent principles that link the neuronal and, consequently, to enhance the salience and the mental levels of description. Sev- of their activity compared to other neurons eral authors have proposed that these mech- (Singer, 1999). anisms mediate several generic features The functional and causal roles of syn- of consciousness, such as unity (Varela & chrony are still an active area of research Thompson, 2001), integration and differen- and depend on the spatial scale at which tiation (Tononi & Edelman, 1998), transi- these phenomena are analyzed. In particular, toriness and temporal flow (Varela, 1999), it is useful to distinguish between two main and awareness of intentional action (Free- scales, short range and long range. Short- man, 1999). In this view, the emergence of a range integration occurs over a local net- specific coherent global assembly underlines work (e.g., columns in the primary visual the operation of any moment of experience. cortex), distributed over an area of approx- The transition from one moment to the next imately 1 cm, through monosynaptic con- would be subserved by desynchronization P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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of some coherent assemblies and the syn- then, more than 100 studies have investi- chronization of new ones. It has also been gated the tonic changes in the ongoing EEG hypothesized that whether a local process from a restful state to a meditative state or participates directly in a given conscious the modulatory, or phasic, effect of medi- state depends on whether it participates tation on the electrical brain responses to in a coherent, synchronous global assembly external sensory stimuli (for reviews, see (Dehaene & Naccache, 2001; Engel et al., Andresen, 2000; Davidson, 1976; Delmonte, 2001). 1984; Fenwick, 1987; Pagano & Warrenburg, Neural synchronies occur in a broad range 1983; Schuman, 1980; Shapiro & Walsh, of frequencies. Fast rhythms (above 15 Hz) 1984; West, 1980, 1987; Woolfolk, 1975). in gamma and beta frequencies meet the The majority of these EEG studies requirement for fast neural integration and focused on the change in the brain’s oscil- thus are thought to play a role in conscious latory rhythms, particularly in the slow fre- processes on the time scale of fractions of quencies (alpha and theta rhythms). It is a second (Tononi & Edelman, 1998; Varela, important to keep in mind that such mea- 1995). Fast-frequency synchronies have been sures reflect extremely blurred and crude found during such processes as attention, estimates of the synchronous processes of sensory segmentation, sensory perception, the ∼1011 neurons in a human brain. Because memory, and arousal. slow oscillations have high electrical voltages Yet neural synchrony must also be under- that make them visually detectable, early stood in the context of the slower alpha and studies only reported coarse visual descrip- theta bands (4–13 Hz), which play an impor- tions of EEGs. Changes in fast-frequency tant role in attention, working memory oscillations during meditation have been (Fries, Reynolds, Rorie, & Desimone, 2001; rarely reported (with the notable exception von Stein, Chiang, & Konig, 2000), and sen- of Das & Gastaut, 1955, and more recently sorimotor integration (Burgess & O’Keefe, Lutz et al., 2004) possibly because the lower 2003; Rizzuto et al., 2003). This evidence voltage of these oscillations requires spec- supports the general notion that neural syn- tral analysis instead of simple visual inspec- chronization subserves not simply the bind- tion. The investigation of fast-frequency syn- ing of sensory attributes, but the overall chrony during meditation has become more integration of all dimensions of a cognitive common since the 1990s following a devel- act, including associative memory, affective oping understanding of its functional role in tone and emotional appraisal, and motor the “binding problem.” planning. In addition to spectral analysis, medita- So far, oscillatory synchrony has been tion has also been characterized with mea- investigated mostly on oscillatory signals sures of coherence or long-distance phase having the same rhythms. More complex synchrony (LDS) (Fries et al., 2001). These non-linear forms of cross-band synchroniza- measures quantify the dynamic coupling tion, so-called generalized synchrony (Schiff, between EEG channels over distant brain So, Chang, Burke, & Sauer, 1996), are also regions. Coherence is the frequency correla- expected and may indeed prove more rele- tion coefficient, and it represents the degree vant in the long run to understanding large- to which the frequency profiles of two dis- scale integration than strict phase synchro- tant areas of the head, as reflected in the nization (Le Van Quyen, Chavez, Rudrauf, electrical signals detected by scalp elec- & Martinerie, 2003). trodes, are similar. LDS measures the instan- Considering the general importance of taneous phase relationship between signals neural synchrony in brain processing, it is not at a given frequency (Lachaux, Rodriguez, surprising that scientists interested in medi- Martinerie, & Varela, 1999). LDS provides a tation have tried to study its electrical brain more direct measure of phase-locking than correlates as early as the 1950s (Das & Gas- coherence because it can separate the effects taut, 1955; Wenger & Bagchi, 1961). Since of amplitude and phase in the interrelations P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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between signals. Thus, LDS can test more occipital-parietal channels particularly when precisely the assumption that phase syn- the eyes are closed, yet alpha activity can chrony is involved in long-distance neu- be recorded from nearly the entire upper ronal integration. Because of the non-linear cortical surface. During wakefulness, it is a nature of brain processes, these linear anal- basic EEG phenomenon that the alpha peak ysis approaches are likely to characterize reflects a tonic large-scale synchronization of only partially the functional properties of a very large population of neurons. This low- synchronous activity. Yet, complementary frequency global neural activity is thought to non-linear analysis of brain dynamics dur- be elicited by reciprocal interactions among ing meditation has only just started to be the cortex, the reticular nucleus, and the tha- explored (Aftanas & Golocheikine, 2002). lamocortical (Delmonte, 1985) cells in other In the selective summary of the liter- thalamic nuclei (Klimesch, 1999; Nunez et ature below, we review only those EEG al., 2001; Slotnick, Moo, Kraut, Lesser, & studies published in top-tier journals and/or Hart, 2002) even if cortico-cortical mech- those that focused on the study of long-term anisms also play a possible role (Lopes da practitioners. Silva, Vos, Mooibroek, & Van Rotterdam, 1980). transcendental meditation Because an overall decrease in alpha TM is a passive meditation adapted for West- power has been related to increasing deman- erners from the Vedic or Brahmanical tradi- ds of attention, alertness, and task load, alpha tions of India. The subject sits quietly, with activity is classically viewed as an “idling the eyes closed, repeating a Sanskrit sound rhythm” reflecting a relaxed, unoccupied (mantra), while concentrating on nothing brain (Klimesch, 1999). Large-scale alpha and letting the mind “drift” (Morse, Martin, synchronization blocks information process- Furst, & Dubin, 1977). The continued prac- ing because very large populations of neu- tice of TM supposedly is said to lead to an rons oscillate with the same phase and expansion of consciousness or the attain- frequency; thus, it is a state of high integra- ment of “cosmic” or “pure, self-referral con- tion but low differentiation. Within a band- sciousness” (Maharishi, 1969). The techni- width of perhaps 2 Hz near this spectral que is described as “easy, enjoyable and does peak, alpha frequencies frequently produce not involve concentration, contemplation or spontaneously moderate to large coherence any type of control” (R. K. Wallace, 1970). (0.3–0.8 over large interelectrode distance The standard EEG correlate of TM is (Nunez et al., 1997). The alpha coher- an increase in alpha rhythm amplitude, fre- ence values reported in TM studies, as a trait quently followed by a slowing in frequency in the baseline or during meditation, belong by 1–3 Hz and a spreading of this pattern into to this same range. Thus a global increase the frontal channels (R. K. Wallace, 1970). of alpha power and alpha coherence might An increase in bursts of theta oscillations (4– not reflect a more “ordered” or “integrated” 7 Hz) has also been reported. Global fronto- experience, as frequently claimed in TM lit- central increases in coherence in alpha (6– erature, but rather a relaxed, inactive mental 12 Hz), as well as in theta frequency ranges state (Fenwick, 1987). between baseline and TM practice, have In contrast, alpha desynchronization been found frequently (for reviews and for a reflects actual cognitive processes in which model of TM practice see Travis, Arenander, different neuronal networks start to oscillate & DuBois, 2004)). locally at different frequencies – typically The dominant frequency in the scalp EEG in higher frequencies (>15 Hz), as well as of human adults is the alpha rhythm. It slower rhythms (4–15 Hz) – and with differ- is manifest by a peak in spectral analysis ent phases, reflecting local processing of spe- around 10 Hz and reflects rhythmic alpha cialized neuronal circuitries, such as those waves (Klimesch, 1999; Nunez et al., 2001). for attention, vision, memory, emotion, Alpha oscillations are found primarily over and so on. Large-scale synchrony between P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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distant neuronal assemblies oscillating at var- physical assertions rather than first-person ious frequencies reflects an active coordina- descriptions, they do suggest that this state tion of functionally independent networks; of absorption could also involve some form in short, it reflects a state of high inte- of meta-awareness. Nevertheless, despite the gration and high differentiation. Thus, the possibility of a more sophisticated phe- slow frequency activity (<13 Hz) found dur- nomenological interpretation and the need ing TM meditation, combined with the fre- to relate physiological data to subjective quent finding of decreased autonomic activ- data, it is still unclear whether and how ity, has been interpreted by many authors TM meditation practices produce increased as reflecting hypoarousal or a relaxed state alpha activity beyond a general arousal effect (Delmonte, 1984; Holmes, 1984; Pagano & or an inhibition of task-irrelevant cortical Warrenburg, 1983). zones. Other relaxation techniques have led Yet, the “idling” model of alpha activity to the same EEG profile, and studies that has been extended recently to account for employed counter-balanced control relax- new findings. Alpha oscillation can, paradox- ation conditions consistently found a lack ically, increase locally over specific regions of alpha power increases or even decreases or also across specific areas while the subject when comparing relaxation or hypnosis to is actively focusing his or her attention on TM meditation (Morse et al., 1977; Tebe- an object or while holding in mind infor- cis, 1975; Warrenburg, Pagano, Woods, & mation (memory load during retention, for Hlastala, 1980). Similarly, the initial claim instance). Slow rhythms (4–12 Hz) can thus that TM produces a unique state of con- also be involved in active mental states sciousness different from sleep has been requiring attention, working memory, or refuted by several EEG meditation studies semantic encoding (Ward, 2003). This alpha that reported sleep-like stages during this model still remains compatible with the technique with increased alpha and then idling model because on this view, alpha theta power (Pagano, Rose, Stivers, & War- rhythms during mental activity reflect active renburg, 1976; Younger, Adriance, & Berger, inhibition of non-task-relevant cortical areas 1975). (Klimesch, 1999). To summarize, alpha global increases and Because TM is described as a passive med- alpha coherence mostly over frontal electro- itation without active control or concentra- des are associated with TM practice when tive effort, the EEG picture found during meditating compared to baseline (Morse, TM meditation can still be interpreted as Martin, Furst, & Dubin, 1977). This global reflecting mainly hypoarousal or a relaxed alpha increase is similar to that produced state. Yet, it is also possible that the ongoing by other relaxation techniques. The pass- repetition of the mantra, which involves, for ive absorption during the recitation of the instance, some form of attention and work- mantra, as practiced in this technique, pro- ing memory, can lead to an active exclusion duces a brain pattern that suggests a decrease of some brain processes compatible with an of processing of sensory or motor informa- increase in alpha activity in non-task-related tion and of mental activity in general. Be- cortical territories. cause alpha rhythms are ubiquitous and fun- TM researchers further view this EEG ctionally non-specific, the claim that alpha picture as reflecting a single and original oscillations and alpha coherence are desir- state of “Transcendental pure consciousness” able or are linked to an original and higher (Maharishi, 1969; Travis et al., 2004). The state of consciousness seem quite premature. transcendental state is conceptualized as a “fourth state of consciousness,” a “wake- attention meditation ful hypometabolic state” that differs from with an object hypnosis and ordinary or sleep states (R. This section regroups EEG studies on med- K. Wallace, 1970). Although these descrip- itative practices having a component of tions might best be interpreted as meta- attention regulation. In all these practices, P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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the intentional structure of a subject/object subjects displayed large alpha activity during remains. As mentioned earlier these tech- periods of rest and increases during medita- niques lie somewhere on a continuum tion (Anand et al., 1961). between two poles of practices: On the one Yet, several exceptions deserve scrutiny. hand, one-pointed attention techniques cul- Two early field studies of Yoga in India by tivate a form of voluntary, effortful, and sus- Das and Gastaut (1955) and Wenger and tained attention on an object, and on the Bagchi (1961), reported a clear sign of auto- other hand, vipa´syan¯a meditation cultivates nomic arousal with increased heart rate and a more broadly focused, non-judgmental skin conductance while advanced yogis med- mode of bare attention. These medita- itate. High-amplitude high-frequency EEG tions differ from relaxation techniques oscillations (beta and gamma) were found because they cultivate a balance between and were more pronounced during deep hypoarousal (Becker & Shapiro, 1981) and meditation (Das & Gastaut, 1955). In a excitation. This balance is required, in well-controlled study, Corby et al. (1978) particular, to maintain a sufficient clarity studied a form of Tantric Yoga meditation or meta-awareness throughout the medi- where the practitioners and controls focused tative session. These practices encompass, on their breath and on the mantra. Unlike for instance, Zazen meditation, Indian yogic previously reported studies, proficient med- concentration, meditation in MBSR, and itators demonstrated increased autonomic one-pointed focused attention. The empha- activation during meditation, whereas unex- sis on stabilizing the mind on an object or perienced meditators demonstrated auto- on the awareness of the intentional rela- nomic relaxation. During meditation, profi- tion itself depends not only on the given cient meditators showed an increase in alpha technique but also likely on the degree of and theta power, minimal evidence of EEG- the practitioner’s accomplishment in a given defined sleep, and a decrease in autonomic practice. orienting to external stimulation. With some important exceptions, most These findings are consistent with the studies on Zazen or India yogic concentra- view described above that alpha and theta tion practices have revealed an EEG signa- activation can also index attentional pro- ture similar to TM as characterized by low- cesses. Becauseee one major feature of atten- ered autonomic arousal and slow-frequency tion is selection, it is likely that the local- EEG patterns (either an increase in alpha or ized increases in slow frequencies reflect an increase in theta activity; Austin, 1998; cortical tuning such that those cortical zones Delmonte, 1984; Fenwick, 1987; Shapiro & that are not required for task engagement Walsh, 1984). This pattern was reported as a are selectively inhibited to facilitate task per- state and sometimes also a trait. For instance, formance (see e.g., Cooper et al., 2003). Kasamatsu and Hirai measured the EEG Also consistent with this formulation are signals of 48 priests and disciples during data on attentional anticipation. Foxe, Simp- Zazen practices (Kasamatsu & Hirai, 1966). son, and Ahlfors (1998) demonstrated that a All subjects exhibited visually an increase cue indicating an upcoming auditory stim- in alpha activity mostly over central and ulus induced increased alpha power over frontal electrodes immediately after begin- parieto-occipital (Blake & Logothetis, 2002) ning meditation. Less experienced subjects cortex, compared when the cue indicated tended to maintain high-amplitude alpha an upcoming visual stimulus. These findings activity throughout the meditative session, are all consistent with the idea that alpha whereas the EEGs of those with more years synchronization during attentional processes of Zazen practice showed a rhythmical theta reflects inhibition of non-relevant areas or wave pattern during the later stage of Zazen process (Klimesch, 1999). Anand, Chhina, and Singh (1961) compared It would be misguided to identify alpha or visually the EEG activity of four advanced theta activity as the sole index of mindful- yogis during rest and during meditation. All ness/awareness meditation. Numerous data P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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suggest that synchronized gamma activity is the specific neural processes that are altered also specifically involved in selective atten- by these practices. tion. In the literature on meditation, one Finally there is some evidence that early study on advanced yogic practition- alpha/theta oscillations during Zazen or ers reported spectacular generalized high- Samadhi practices differ functionally from amplitude beta/gamma oscillations during the alpha/theta activity during a relaxed intense internal concentration of attention non-meditative state. An early model of (Das & Gastaut, 1955). We also found an meditation proposed that “de-automization” increase in fast-frequency oscillations dur- was induced, such that each stimulus trial ing samatha practice (unpublished data). was perceived as “fresh” during medita- Numerous studies of humans, as well as ani- tive states cultivating a receptive and open mals, have demonstrated an enhancement awareness (Deikman, 1966; Kasamatsu & of the gamma activity when subjects were Hirai, 1966). A possible indication of this actively attending to a certain stimulus or process is EEG alpha blocking, which is simply perceived an object (Tallon-Baudry & defined as a decrease in ongoing alpha (8– Bertrand, 1999). Such synchronized gamma 12 Hz) power when comparing prestimu- activity during attention participates not lus to post-stimulus activity. Typically alpha only in bottom-up processes (e.g., sensory activity is reduced from closed eyes to open segmentation, feature extraction) but also in eyes or when discrete stimuli are presented top-down processes (Engel et al., 2001). and is thought to reflect cortical process- Slow and fast-frequency rhythms inter- ing. This response habituates after repeti- act in the brain. For instance, in intracra- tive stimulus presentations (Morrell, 1966). nial recordings from area V4 in monkeys, Early field studies on yogis reported no alpha increased gamma range synchronization, but blocking in response to auditory, thermal, reduced low-frequency synchronization, is and visual stimuli (Anand et al., 1961; Das observed among neurons activated by the & Gastaut, 1955; Wenger & Bagchi, 1961). attended stimulus as compared to neurons Subsequent Zen studies found alpha block- activated by an identical but non-attended ing to auditory sounds but without habitua- stimulus (Fries et al., 2001). These impor- tion (Kasamatsu & Hirai, 1966). Early TM tant results, as well as event-related data, studies produced conflicting results, with lead to the notion of a surround inhibi- one finding an absence of alpha blocking, tion wherein active cortical areas, indexed whereas the other reported habituation of by alpha desynchronization and/or fast- alpha blocking to auditory stimuli (Banquet, frequency synchronies, are surrounded by a 1973; R. K. Wallace, 1970). “doughnut” of alpha synchronization or inhi- A replication and extension of these find- bition (Suffczynski, Kalitzin, Pfurtscheller, ings were attempted (Becker & Shapiro, & Lopes da Silva, 2001). This balance 1981). Experienced Zen, Yoga, and TM med- between slow and fast frequencies can be itators, and “attend” and “ignore” groups of detected under specific experimental condi- controls were presented with auditory clicks tions, such as intracranial recording or sim- during mediation. The attend group was ple event-related tasks, over motor or sen- asked to “pay strong attention” to each click, sory areas. Yet, this distinction is likely to be notice all of its sound qualities and subtleties, blurred in general while recording ongoing and count the number of clicks; the ignore EEG signals because of volume conduction group was told “try not to let the clicks dis- (i.e., a single neural source is likely to influ- turb your relaxed state.” EEG alpha sup- ence the signal in many recording channels). pression and skin conductance response both Despite this limitation, the combined char- showed clear habituation, which did not dif- acterization of fast-frequency synchronies, fer among groups, thus failing to replicate in addition to the slow frequencies, over var- the earlier studies. ious topographical regions of the scalp is As a summary, these meditation prac- likely to provide increased understanding of tices that feature focused attention on P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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objects most frequently are accompanied by had a peak-to-peak amplitude of the order increases in alpha and theta power, but also of dozens of microvolts for several prac- by fast frequencies (beta and gamma) during titioners. High-amplitude oscillations were deep meditation. The slow-frequency activ- continuous during the meditation over sev- ity overlaps notably with early drowsiness eral dozens of seconds and gradually increase and sleep stages even if these oscillations during the practices. These EEG patterns potentially differ functionally. The neuro- differ from those of controls, in particular electric signatures of these various medi- over lateral fronto-parietal electrodes. Some tative techniques (Focus Attention, Zazen, preliminary data further suggest that these Vipasyan´ a¯ meditation) have not yet been ongoing high-amplitude gamma oscillations firmly established. Our current understand- are correlated with self-reports of the clarity ing of attention suggests that the selection (see the section on samatha and vipa´syan¯a or the exclusion from attention of particu- as paradigms of meditation; Lutz et al., lar contents (sensory, motor, internal tasks) 2005). is correlated with the activation or inhibi- These new findings are similar to the early tion of specific brain areas, as indexed by report of Das and Gastaut (1955) during the specific changes in selective brain oscillatory Samadhi of advanced Indian Yogis. Samadhi patterns. The combination of topographical was defined as a state during which “the information with spectral information seems perfectly motionless subject is insensible to a promising method by which to delineate all that surrounds him and is conscious of further these various meditative techniques. nothing but the subject of his meditation.” Das and Gastaut (1955) reported an accel- objectless meditation eration of the cardiac rhythm during med- During objectless meditation, such as Open itation almost perfectly parallel to that of Presence or Non-Referential Compassion the EEG. The EEG showed progressive and meditation, it is said that the practitioner spectacular modifications during the deep- does not focus on a particular object but est meditations in those subjects who had rather cultivates a state of being. Object- the longest training: acceleration of the alpha less meditation does so in such a way that, rhythm and decrease in the amplitude and according to reports given after meditation, appearance of faster oscillations (>20 Hz). the intentional or object-oriented aspect of These fast frequencies (beta (25–30 Hz) experience appears to dissipate in medita- and sometimes even gamma activity (40–45 tion along with the explicit sense of being a Hz) became generalized during the Samadhi perceiver or an agent (autobiographical self). meditation, with high amplitude reaching One working hypothesis is that some form of between 30–50 mV. meta-awareness or, more precisely, of some In our study (Lutz et al., 2004), we fur- mere ipseity still remains or is enhanced dur- ther showed that during this objectless med- ing these states. itation the ratio of fast-frequency activity These types of meditation have been (25–42 Hz) to slow oscillatory activity (4–13 poorly investigated so far. We studied a Hz) over medial fronto-parietal electrodes is group of long-term practitioners who under- initially higher in the resting baseline before went mental training in the same Tibetan meditation for the practitioners than the Nyingmapa and Kargyupa traditions for controls (Figure 19.4). During meditation, 10,000 to 50,000 hours over time periods this difference increases sharply over most of ranging from 15 to 40 years. We found the scalp electrodes and remains higher than that these long-term Buddhist practitioners the initial baseline in the post-meditative self-induced sustained EEG high-amplitude baseline. The functional and behavioral con- gamma-band oscillations and phase syn- sequences of sustained gamma activity dur- chrony during Non-Referential Compassion ing objectless meditation are not currently meditation (Lutz et al., 2004, Figure 19.5). known, and such effects clearly need further These fast-frequency oscillations (>20 Hz) study. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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a μV 20 F3 −20 20 Fc5 −20 20 Cp5 −20 20 F4 −20 20 Fc6 −20 20 Cp6 −20 b μV2 500 300 100 c % 14 12 10 0 50100 150 Time (s)

Resting state Meditative state Block colors: (1) (2) (3) (4) Figure 19.5. Example of high-amplitude gamma activity during the non-referential compassion meditation of long-term Buddhist practitioners. a. Raw electroencephalographic signals. At t = 45 s, practitioner S4 started generating a state of non-referential compassion, block 1. b. Time course of gamma activity power over the electrodes displayed in “a” during four blocks computed in a 20-s sliding window every 2 s and then averaged over electrodes. c. Time course of their cross-hemisphere synchrony between 25–42 Hz. The density of long-distance synchrony above a surrogate threshold was calculated in a 20-ssliding window every 2 s and for each cross-hemisphere electrode pairs and, then, was averaged across electrode pairs (adapted from Lutz et al. 2004).

Neuroimaging Correlates of Meditation neural basis of the peak experience of a meditative state termed “kensho” or “satori” At this stage neuroimaging studies on in Japanese Zen Buddhism. In this state, meditation are typically more exploratory the sense of selfhood is allegedly dissolved than hypothesis driven. Nevertheless, some and an “unattached, self-less, impersonal” progress has been made in the identiﬁca- awareness remains (this state shares a strong, tion of structural-functional brain relation- descriptive similarity with the Open Pres- ships of meditative states and traits using a ence state discussed above). After examin- variety of neuroimaging modalities. In par- ing the precise experiential changes induced ticular, some theoretical efforts have been by this state, he reviewed the various phys- made to localize the neural circuitry selec- iological subsystems that might participate tively engaged during a meditative state. in this state. Austin speciﬁcally introduces Austin (1998), for instance, elegantly com- the distinction between “egocentric” neu- bined his insight as a Zen practitioner with ral networks involved in the generation of a his neuroanatomical knowledge of the brain multifaceted self situated in time and space as a medical doctor to speculate about the and “allocentric” neural networks involved P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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in the mere processing of the external envi- characterize the physiology and neurochem- ronment. For Austin, neural networks par- istry of the working brain. SPECT (single ticipating in the construction of the narra- photon emission computed tomography) is tive self could be shut down during Kensho, another neuroimaging method that is similar specifically through thalamic gating origi- to, though less sophisticated than PET, and nating from the reticular formation. At the it produces images of neurochemical func- same time, he proposes that the state of tion that have less spatial resolution than hyperawareness during this practice is medi- PET. MRI uses magnetic fields and radio ated by intralaminar nuclei of the thala- waves to produce high-quality two- or three mus that can increase the fast-frequency syn- dimensional images of brain structures with- chrony in other cortical regions. These nuclei out injecting radioactive tracers. Using MRI, could shape the resonance of the cortico- scientists can see both surface and deep brain thalamo-cortical loops and functionally alter structures with a high degree of anatomi- the neural processing in these egocen- cal detail (millimeter resolution). MRI tech- tric/allocentric networks. These proposals niques can also be used to image the brain as (Austin, 1998, 2006) are clearly specula- it functions. tive, and further discussion is beyond the Functional MRI (fMRI) relies on the mag- scope of this review. Nevertheless, Austin’s netic properties of blood to enable the work amply illustrates the potential bene- researcher to measure the blood flow in the fits that may come when the neuroscience of brain as it changes dynamically in real time. meditation and first-person descriptions are Thus researchers can make maps of changes brought into a dynamic dialogue that com- in brain activity as participants perform var- bines their findings in a manner that places ious tasks or are exposed to various stim- fruitful constraints on each. uli. An fMRI scan can produce images of Although there is considerable potential brain activity as fast as every second or two, for advancement in neuroscience through whereas PET usually takes several dozens neuroimaging studies of meditation, the of seconds to image brain function. Thus, number of published studies remains sparse. with fMRI, scientists can determine pre- To illustrate the range of methods and ques- cisely when brain regions become active and tions utilized thus far, we now review briefly how long they remain active. As a result, the published research in this area. they can see whether brain activity occurs simultaneously or sequentially in different brain imaging techniques used brain regions as a participant thinks, feels, or in meditation research reacts to external stimuli. An fMRI scan can Positron emission tomography (PET; Blake also produce high-quality images that can & Logothetis, 2002) and functional magnetic identify more accurately than PET which resonance imaging (fMRI) are two func- areas of the brain are being activated. In sum- tional brain imaging methods that have been mary, fMRI offers better image clarity along used to study meditation. PET measures with the ability to assess blood flow and brain emissions from radioactively labeled chemi- function in seconds. So far, however, PET cals that have been injected into the blood- retains the advantage of being able to pin- stream and uses the data to produce two- or point which neurochemicals are involved in three-dimensional images of the distribution functional brain alterations. of the chemicals throughout the brain and body. Using different tracers, PET can reveal early neuroimaging studies on blood flow, oxygen and glucose metabolism, relaxation practice and meditation and neurotransmitter concentrations in the The studies from Lou et al. (1999) and tissues of the working brain. Blood flow and Newberg et al. (2001) provide the first evi- oxygen and glucose metabolism reflect the dence of functional brain changes using PET amount of brain activity in different regions, or SPECT during a relaxation practice and and this type of data enables scientists to a meditative practice, respectively. Even if P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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these studies offer new insights about these prefrontal cortex participates in working states, they speak also for the need to more memory and the preparation for voluntary precisely develop descriptions of the prac- movement, the anterior cingulate plays a tices to better understand just what the func- role not only in motivation and resolution tional neural changes are reflecting. of conflict but also skeleto-motor control Yoga Nidra,¯ literally “Yoga-Sleep,” is a and executive attention, and the cerebellum state in the Yoga tradition in which con- is implicated in cognitive functions such as sciousness of the world and consciousness attention. of action are meant to be dissociated: The Lou et al. (1999) interpreted these results mind “withdraws” from wishing to act and is as reflecting dissociation between two com- not associated with emotions or the power plementary aspects of consciousness: the of will. The practitioner allegedly becomes conscious experience of the sensory world a neutral observer who experiences the loss and the “fact or illusion of voluntary control, of conscious control, concentration, or judg- with self regulation.” Unfortunately, the lack ment, yet maintains an equal and impar- of a control population makes it difficult to tial attention to sensory awareness, which interpret whether the brain patterns reflect 15 is said to be enhanced. A PET ( O-H2 O) specific meditative qualities or the cognitive study of blood flow changes during Yoga processes induced by the instructions. Nidra¯ practice was carried out while subjects Using SPECT Newberg et al. (2001) listened to a tape recording, with guided measured changes in regional blow flow instructions on the different phases of the (rCBF) while eight relatively experienced practice (Lou et al., 1999). The relaxation Tibetan Buddhist practitioners meditated. tape contained focusing exercises on body The practitioners practiced daily for at least sensation, abstract joy, visual imagery of a 15 years and underwent several 3-month summer landscape, and symbolic represen- retreats. In the scanner, the practitioners tation of the self. Participants listened to were instructed to “focus their attention on a the tape and followed the instructions of visualized image and maintained that focus the guided meditation. The baseline con- with increasing intensity.” In constrast to Lou dition was obtained by replaying the tape et al. (1999), Newberg and colleagues (2001) while participants remained neutral (i.e., reported an increase in activity in orbital they did not follow the instructions). Each frontal cortex, dorsolateral prefrontal cortex of the guided meditation phases was associ- (DLPFC), and thalamus. They also found ated with different regional activations dur- a negative correlation between the DLPFC ing meditation relative to the control con- and the superior parietal lobe, which was ditions. Yet, during all meditative phases, interpreted as reflecting an altered sense of overall increases in bilateral hippocampus, space experienced during meditation. The parietal, and occipital sensory and associa- difference in the frontal areas between their tion regions were found compared to control finding and that of Lou et al. (1999)was conditions. This pattern suggests an increase viewed as reflecting a difference between an of activity in areas involved in imagery. active and a passive form of meditation. Deactivation was found during medita- In addition to the fact that no con- tion in orbitofrontal, dorsolateral prefrontal, trol participants were involved in the New- anterior cingulate cortices, temporal and berg study, there is regrettably a lack of inferior parietal lobes, caudate, thalamus, descriptive precision of the meditative state pons, and cerebellum. This differential activ- that was studied. This limitation will ham- ity was interpreted as reflecting a “tonic” per the future comparison of this study activity during normal consciousness in the with others. More precisely, a broad vari- baseline condition. The areas decreasing dur- ety of Tibetan meditative techniques could ing the meditation state are known to par- encompass the provided meditative descrip- ticipate in executive function or control tions. These practices include, for instance, of attention. More particularly, dorsolateral Focused Attention on a mental object, or any P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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meditation on the visualization of a deity, dard meditation, the participants concen- or indeed the visualization of one’s guru. trated their attention on an external visual Unfortunately, these practices can differ or object (a white dot on the screen), gently even be opposite in terms of their motiva- bringing attention back to the object if they tions or emotional qualities. For instance, the became distracted or sleepy. Control sub- visualization of deities could involve some jects with no prior meditative training were invocation of anger or lust, whereas the visu- given instruction in concentration medita- alization of the guru is meant to induce tion with daily practice a week before the a strong devotional affect in the medita- fMRI scan. fMRI of concentration meditator. Because the independent variable (i.e., tion in both the experienced meditators and the specific meditative practice) was only the controls showed common areas of acti- vaguely described in this study, its impact vation in the traditional attention network, is limited. including such areas as the intraparietal sulci, frontal eye fields (FEF), thalamus, insula, focused attention/minfulness- lateral occipital, and basal ganglia. How- awareness meditation ever, experienced meditators showed more A form of Kundalini Yoga using mantra rep- activation, especially in the frontal-parietal etition combined with breath awareness was network. The increased activation in these assessed with fMRI (Lazar et al., 2000). The regions for experienced practitioners may control state entailed the mental enuncia- represent a neural correlate for these sub- tion of animal names. Five Yoga adepts who jects’ expertise in sustained attention. The had practiced Kundalini Yoga for at least fact that controls show greater activation in 4 years served as subjects. An increase in the anterior cingulate compared with the the Blood Oxygenation Level Dependent adepts may reflect greater error proneness (BOLD) signal was found from baseline to (i.e., distraction) and conflict monitoring in meditation in the putamen, midbrain, ante- the controls than the adepts; the conflict rior cingulate cortex, and the hippocam- would be between the instructions to focus pal/parahippocampal formation, as well as and the difficulty of complying with such in regions in the frontal and parietal cor- instructions. tices. The comparison of early versus late Taken together these two brain imaging meditation states showed activity increase studies show that concentration meditation in these regions, but within a greater area enhances processing in regions similar to and with larger signal changes later in the those found in other attentional paradigms. practice. Because the pattern of brain activ- The group differences between long-term ity increased with meditation time, it may practitioners and novices support the view index the gradual changes induced by medi- that attention processing could be affected tation. This pattern of activity encompassed by mental training. areas subserving attention (fronto-parietal cortices) and areas subserving arousal and pure compassion and autonomic control (limbic regions, mid- lovingkindness meditation brain, and anterior cingulate cortex). Using functional imaging, we assessed In another attention-related study, we brain activity while novice and long-term recently studied experienced Buddhist med- practitioners generated a Lovingkindness- itators (>10,000 hours of cumulative med- Compassion meditation, alternating with itation practice) and newly trained control a resting state (Brefczynski-Lewiset et al., subjects while they performed a Focused 2004). As described in the section on Non- Attention meditation (Tsé-cig Ting-ngé-dzin; Referential Compassion meditation, this see the section on Focused Attention), alter- standard Buddhist meditation involves the nating with a passive state, while undergo- generation of a state in which an uncon- ing block-design fMRI (Brefczynski-Lewis, ditional feeling of lovingkindness and com- Lutz, & Davidson, 2004). During this stan- passion pervades the whole mind as a P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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way of being, with no other considera- using pain experience or interoceptive tasks tion, reasoning, or discursive thoughts. This (Craig, 2002). state is called in Tibetan “pure” or “non- Finally, love and compassion require an referential” compassion, as the practitioner understanding of the feelings of others; is not focused upon particular objects dur- hence, a common view is that the very ing this state. In the resting state the subjects regions subserving one’s own feeling states were asked to be in the most ordinary state also instantiate one’s empathic experience without being engaged in an active mental of other’s feelings. This framework derives state or being in a pleasant or unpleasant from perception-action models of motor emotional state. Subjects were eight long- behavior and imitation. The key proposal term Buddhist practitioners and eight age- is that the observation and imagination of matched healthy control volunteers who another person in a particular emotional were interested in learning to meditate. state automatically activate a similar affec- Buddhist practitioners underwent mental tive state in the observer, with its associated training in the Tibetan Nyingmapa and Kar- autonomic and somatic responses. Thus, gyupa traditions for 10,000 to 50,000 hours experienced and empathic pain commonly over time periods ranging from 15 to 40 activated the anterior insula and rostral ante- years. During the meditative state, we found rior cingulate cortex (Singer et al., 2004). a common activation in the striatum, ante- The activation in the anterior insula was rior insula, somatosensory cortex, anterior stronger for the practitioners, an area that cingulate cortex, and left-prefontal cortex some scientists have found to be involved in and a deactivation in the right interior pari- feelings. These data are consistent with the etal. This pattern was robustly modulated view that our experience of another’s suf- by the degree of expertise, with the adepts fering is mediated by the same brain regions showing considerably more enhanced acti- involved in the experience of our own pain. vation in this network compared with the We further found that brain activity for novices. the long-term practitioners was greater than These data provide evidence that this the novices in several of the commonly acti- altruistic state involved a specific matrix of vated regions. These analyses indicate that brain regions that are commonly linked to the degree of training, as reflected in the feeling states, planning of movements, and hours of cumulative meditation experience, positive emotions. Maternal and romantic modulates the amplitude of activation in the love have been linked in humans to the acti- brain areas commonly involved in this state. vation of the reward and attachment cir- To summarize, our study of Compas- cuitries, such as the substantia nigra and sion meditation found activation in brain the striatum (caudate nucleus, putamen, regions thought to be responsible for moni- globus pallidus; Bartels & Zeki, 2004). Pos- toring one’s feeling state, planning of move- itive and negative emotions are expected to ments, and positive emotions. This pattern differentially activate the left and right pre- was robustly modulated by the degree of frontal cortices, respectively, as suggested by expertise. These data suggest that emotional lesion and electrophysiological data (David- and empathic processes are flexible skills son, 2000). More generally, feeling states that can be enhanced by training and that are thought to be mediated by structures such training is accompanied by demonstra- that receive inputs regarding the internal ble neural changes. milieu and musculoskeletal structures and include the brainstem tegmentum, hypotha- lamus, insula, and somatosensory and cin- General Conclusion gulate cortices (Damasio, 1999). This view has received some neuroimaging support in Overall, this chapter aimed to summa- a task where subjects self-generate emo- rize the state of knowledge in neuro- tional states and more recently in studies scientific research on meditation and to P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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suggest potential avenues of inquiry illu- health, illness, and possibly well-being. We minated by these initial findings. The then suggested how the use of first-person first section discussed the need for more expertise might foster our understanding of precise descriptions of meditative prac- the neural counterpart of subjective expe- tices so as to define properly the prac- rience. These intersections between neuro- tices that are the objects of scientific science and meditation were separated here study. Following this recommendation, the mainly for analytical purposes, but these Buddhist contemplative tradition was pre- heuristic distinctions implicitly suggest an sented in detail as a canonical example. The important area of further research; namely, main Buddhist theories of meditation were the interactions among the various themes of reviewed as well as the basic parameters research. For instance, one question of inter- that define most forms of Buddhist con- est will be to explore whether it is mean- templative practice. In addition to suggest- ingful to study the alleged therapeutic or ing an approach to defining and categoriz- healing virtues of meditation as a variable of ing meditation, this section also aimed to research in isolation from other issues. The underscore the difficulty of separating well- interest in this question stems from the pos- defined first-person descriptions of medita- sibility that the beneficial changes found in tive states from other claims that, although practitioners of meditation are intrinsically apparently descriptive, are best understood dependent on other practices or virtues cul- as reflecting particular cultural or religious tivated in their tradition, such as compas- exigencies that are not strictly rooted in sci- sion, ethical behavior, or a first-person explo- entifically tractable observations. The choice ration of the nature of the self and external to view a Buddhist claim as a first-person perception. Having suggested, in any case, description of an actual state or as primar- the potentially fruitful exploration of medi- ily a product of some religious and cultural tation from a neuroscientific perspective, in rhetoric is certainly subject to debate and the final section, we reviewed the most rel- interpretation. Further developments will evant neuroelectric and neuroimaging find- definitely be needed to delineate these dis- ings of research conducted to date. We antic- tinctions. With these difficulties in mind, ipate that the renewed interest in research three standard Buddhist meditative states on meditation will probably extend and pos- were described in detail, as well as the sibly modify this section within the near rationale for the cultivation of these states future. and the expected post-meditative effects. As noted earlier, we chose to emphasize Some general guidelines were then pro- the practice of long-term Buddhist practi- posed for developing a questionnaire to tioners, in part because of the potential that define more precisely a practice under exam- a study of such practitioners might have ination. It is our hope that this first sec- to enhance our understanding of conscious- tion will provide researchers with some ness. Already we have some indication that theoretical and methodological principles experienced practitioners are able to pro- to clarify and enhance future research on vide repeatable subjective reports that are meditation. more reliable than those from untrained per- The second section explored some sci- sons, and this opens the door to wide-ranging entific motivations for the neuroscientific research into the neural correlates of those examination of meditation in terms of its reportable states. More particularly, the pos- potential impact on the brain and body of sibility that some meditators may be able long-term practitioners or its possible role in to induce a state approaching some form of the neuroscientific study of subjective expe- bare consciousness or ipseity raises the tan- rience. After an overview of the mechanisms talizing (if contentious) hypothesis that the of neuroplasticity and mind-body interac- neural correlates of such a state would bring tion, we argued that mental training might us closer to understanding what we mean have a long-term impact on the brain and by consciousness from a neuroscientific per- body in a way that is beneficial for physical spective. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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Our decision to focus on long-term Bud- Religion, Emory University, 537 Kilgo Cir- dhist practitioners, however, should not cle, Emory University, Atlanta, GA 30322. diminish the importance of future research Email: [email protected]. on novices, of longitudinal studies of changes over time in novice or mid-range practitioners, or of research involving other contemplative traditions. This point is crucial Notes if one believes that some of these meditative practices have the potential to evolve 1. Number of articles indexing the term “medi- into a more secular form of mental train- tation” in Medline in 2005. ing, with alleged therapeutic, pedagogical, 2. For a fruitful and pragmatic development of and/or health value. Most importantly, the this hypothesis see Depraz, Varela, & Vermer- collective evidence showcased in this review sch (2003). underscores the fact that many of our core 3. To facilitate further inquiry by readers unfa- mental processes, such as awareness and miliar with the relevant Asian languages, only attention and emotion regulation, including sources available in English have been used to our very capacity for happiness and com- present the pertinent Buddhist theories and practices. It is important to note, however, that passion, should best be conceptualized as many of the most relevant Tibetan texts in par- trainable skills. The meditative traditions ticular have yet to be translated reliably into provide a compelling example of strategies any European language. and techniques that have evolved over time 4. Gethin (1998) provides an excellent overview to enhance and optimize human potential of the Abhidharma and its context. It is impor- and well-being. The neuroscientific study of tant to note that the two classical South Asian these traditions is still in its infancy, but languages most relevant to the history of liv- the early findings promise both to reveal ing Buddhist traditions are Sanskrit and Pali.¯ the mechanisms by which such training may Sanskrit is relevant especially to Tibetan, Chi- exert its effects and underscore the plastic- nese, Japanese, and Korean Buddhism. Pali¯ is ity of the brain circuits that underlie com- still a scholarly language of the Theravada¯ Bud- plex mental functions. It is our fervent hope dhist traditions that are active especially in ´ that this review will stimulate additional Sr¯ıLanka,˙ Thailand, and Myanmar. For con- sistency, we have used Sanskrit for technical research and will lead to the increased use of terms that apply generally to Buddhist tradi- these practices in a wide range of everyday tions, but some academic sources will favor the contexts. Pali¯ equivalents. In such sources, Abhidharma would be rendered as Abhidhamma. 5. In English, the term “lovingkindness” is often Authors Note used in lieu of “compassion” because it more accurately translates the Sanskrit compund, Support for writing this chapter and the maitr¯ıkarun. a¯. This compound consists of two research from the authors’ lab that is terms: maitr¯ı, translated as “loving,” is defined reported herein was provided by NIMH as the aspiration for another to be happy, and P50-MH069315 to RJD, gifts from Adrianne karun. a¯, translated as “kindness,” is defined as and Edwin Cook-Ryder and from Bryant the aspiration that another be free of suf- Wangard, NCCAM U01AT002114-01A1 and fering. The term karun. a¯ is also translated as “compassion,” and in Tibetan it is rendered the Fyssen Foundation. Address correspon- as snying rje, the term that occurs in “non- dence to Antoine Lutz or Richard J. David- referential compassion” (dmigs med snying son, W. M. Keck Laboratory for Functional rje; Skt., niralambanakarun. a)¯ . Nevertheless, Brain Imaging and Behavior, Waisman Cen- even though the most accurate translation of ter, 1500 Highland Avenue, Madison, WI this compound should include only the word 53705-2280. Email: [email protected] “compassion,” the actual practice of generating and [email protected]. Address correspon- this state involves both love and compassion; dence to John D. Dunne, Department of that is, both maitr¯ı and karun. a.¯ P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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References and beta oscillations and the plasticity of exci- tatory and inhibitory synapses: A network 4 1634 Aftanas, L. I., & Golocheikine, S. A. (2002). model. Journal of Neurophysiology, 88( ), – 1654 Non-linear dynamic complexity of the human . EEG during meditation. Neuroscience Letters, Blake, R., & Logothetis, N. K. (2002). Visual com- 330(2), 143–146. petition. Nature Reviews Neuroscience, 3(1), 13– 21. Anand, B., Chhina, G., & Singh, B. (1961). Some aspects of electroencephalographic studies in Brefczynski-Lewis, J. A., Lutz, A., & Davidson, R. 2004 yogis. Electroencephalography and Clinical Neu- J. ( ). A neural correlate of attentional exper- rophysiology, 13, 452–456. tise in long-time Buddhist practitioners. (Report no. 715.8.). San Diego: Society for Neuro- Andresen, J. (2000). Meditation meets behav- science. ioural medicine: The story of experimental 1986 research on meditation. Journal of Conscious- Bronkhorst, J. ( ). The two traditions of medi- 28 ness Studies, 7, 17–73. tation in ancient India ( th ed.). Stuttgart: F. Steiner Verlag Wiesbaden. Apple, J. (2003). Twenty varieties of the Samgha: 2003 A typology of noble beings (arya)¯ in Indo- Burgess, N., & O’Keefe, J. ( ). Neural repre- Tibetan scholasticism. Part 1. Journal of Indian sentations in human spatial memory. Trends in 12 517 519 Philosophy, 31(5–6), 503–592. Cognitive Science, 7( ), – . 2006 Austin, J. H. (1998). Zen and the brain: Toward Cahn, R., & Polich, J. ( ). Meditation an understanding of meditation and conscious- states and traits: EEG, ERP, and neuroimag- 132 180 ness (2nd ed.). Cambridge, MA: MIT Press. ing studies. Psychological Bulletin, , – 211. Austin, J. H. (2006). Zen-brain reﬂections. Review- Carter, O. L., Presti, D. E., Callistemon, C., ing recent developments in meditation and con- Ungerer, Y., Liu, G. B., & Pettigrew, J. D. sciousness. Cambridge, MA: MIT Press. (2005). Meditation alters perceptual rivalry 1973 Banquet, J. P. ( ). Spectral analysis of the EEG in Tibetan Buddhist monks. Current Biology, in meditation. Electroencephalography & Clini- 15(11), R412–413. cal Neurophysiology, 35(2), 143–151. Clark, D. D., & Sokoloff, L. (1999) Circulation 2003 Barinaga, M. ( ). Buddhism and neuro- and energy metabolism of the brain. In G. J. science. Studying the well-trained mind. Sci- Siegel, B. W. Agranoff, R. W. Albers, S. K. 5642 44 46 ence, 302( ), – . Fisher, & M. D. Uhler (Eds.), Basic neurochem- Bartels, A., & Zeki, S. (2004). The neural corre- istry. Molecular, cellular and medical aspects. lates of maternal and romantic love. Neuroim- Philadelphia: Lippincott-Raven. 3 1155 1166 age, 21( ), – . Coleman, J. W. (2002). The new Buddhism: The Becker, D. E., & Shapiro, D. (1981). Physiologi- Western transformation of an ancient tradition. cal responses to clicks during Zen, Yoga, and New York: Oxford University Press. 6 694 TM meditation. Psychophysiology, 18( ), – Cooper, N. R., Croft, R. J., Dominey, S. J., 699 . Burgess, A. P., & Gruzelier, J. H. (2003). Para- Benson, H., Lehmann, J. W., Malhotra, M. S., dox lost? Exploring the role of alpha oscilla- Goldman, R. F., Hopkins, J., & Epstein, M. D. tions during externally vs. internally directed (1982). Body temperature changes during the attention and the implications for idling and practice of Tum-mo yoga. Nature, 295(5846), inhibition hypotheses. International Journal of 234–236. Psychophysiology, 47(1), 65–74. Berger, H. (1929). Uber das Elektrenke- Corby, J. C., Roth, W. T., Zarcone, V. P., Jr., & laphogramm des Menschen. Archiv fur ¨ Psy- Kopell, B. S. (1978). Psychophysiological cor- chiatrie und Nervenkrankheiten, 87, 527–570. relates of the practice of Tantric Yoga medita- Beyer, S. (1977). Notes on the vision quest tion. Archives of General Psychiatry, 35, 571– in early Mahay¯ ana.¯ In L. Lancaster (Ed.), 577. Praj˜n¯ap¯aramit¯a and related systems (pp. 329– Cosmelli, D., David, O., Lachaux, J. P., Mar- 340). Berkeley, CA: University of California tinerie, J., Garnero, L., Renault, B., & Varela, Press. F. (2004). Waves of consciousness: Ongo- Bibbig, A., Traub, R. D., & Whittington, M. A. ing cortical patterns during binocular rivalry. (2002). Long-range synchronization of gamma Neuroimage, 23(1), 128–140. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

meditation and the neuroscience of consciousness 545

Cozort, D. (1986). Highest yoga tantra: An intro- Depraz, N., Varela, J. F., & Vermersch, P. (2003). duction to the esoteric Buddhism of Tibet. Ithaca, On becoming aware: A pragmatics of experienc- NY: Snow Lion Publications. ing. Amsterdam: John Benjamins. Craig, A. D. (2002). How do you feel? Engel, A. K., Fries, P., & Singer, W. (2001). Interoception: The sense of the physiological Dynamic predictions: Oscillations and syn- condition of the body. Nature Reviews Neuro- chrony in top-down processing. Nature Reviews science, 3(8), 655–666. Neuroscience, 2 (10), 704–716. Dalai Lama XIV [ = Bstan-’dzin-rgya-mtsho]. English, E. (2002). Vajrayogin¯ı, a study of her visu- (1991). Path to bliss. Ithaca, NY: Snow Lion alizations, rituals & forms: A study of the cult of Publications. Vajrayogin¯ı in India. Boston: Wisdom Publica- Dalai Lama XIV [ = Bstan-’dzin-rgya-mtsho]. tions. (1995). The world of Tibetan Buddhism: An Fenwick, P. B. (1987). Meditation and the EEG. overview of its philosophy and practice. Boston: In A. West (Ed.), The psychology of meditation Wisdom Publications. (pp. 104–117). New York: Clarendon Press. Damasio, A. R. (1999). The feeling of what Fischer, R. (1971). A cartography of the ecstatic happens: Body and emotion in the making of con- and meditative states. Science, 174(12), 897– sciousness. New York: Harcourt Brace. 904. 1998 Das, N. N., & Gastaut, H. C. (1955). Variations de Foxe, J. J., Simpson, G. V., & Ahlfors, S. P. ( ). 10 l’activite electrique du cerveau, du coeur et des Parieto-occipital approximately Hz activ- muscles squelletiques au cours de la medita- ity reﬂects anticipatory state of visual atten- 17 3929 tion et de l’extase yogique. Electroencephalogra- tion mechanisms. Neuroreport, 9( ), – 3933 phy & Clinical Neurophysiology, 6(suppl.), 211– . 219. Freeman, W. (1999). Consciousness, intentional- Davidson J. M. (1976). The physiology of med- ity, and causality. Journal of Consciousness Stud- 143 172 itation and mystical states of consciousness. ies, 6, – . Perspect Biol Med. 19(3):345–79. Fries, P., Reynolds, J. H., Rorie, A. E., & Des- 2001 Davidson, R. J. (2000). Affective style, psy- imone, R. ( ). Modulation of oscillatory chopathology, and resilience: Brain mecha- neuronal synchronization by selective visual 5508 nisms and plasticity. American Psychologist, attention [see comment]. Science, 291( ), 1560 1563 55(11), 1196–1214. – . Davidson, R. J., Kabat-Zinn, J., Schumacher, J., Fries, P., Roelfsema, P. R., Engel, A. K., Konig, P., 1997 Rosenkranz, M., Muller, D., Santorelli, S. F., & Singer, W. ( ). Synchronization of oscil- Urbanowski, F., Harrington, A., Bonus, K., latory responses in visual cortex correlates with & Sheridan, J. F. (2003). Alterations in brain perception in interocular rivalry. Proceedings of 23 and immune function produced by mindful- the National Academy of Sciences USA, 94( ), 12699 12704 ness meditation [see comment]. Psychosomatic – . Medicine, 65(4), 564–570. Gethin, R. (1998). The foundations of Buddhism. Dehaene, S., & Naccache, L. (2001). Towards a Oxford: Oxford University Press. cognitive neuroscience of consciousness: Basic Glaser, D. (2000). Child abuse and neglect and evidence and a workspace framework. Cogni- the brain – a review. Journal of Child Psychol- tion, 79(1–2), 1–37. ogy & Psychiatry & Allied Disciplines, 41(1), 97– 116 Deikman, A. J. (1966). Implication of experimen- . tally induced contemplative meditation. Jour- Grossman, P., Niemann, L., Schmidt, S., & nal of Nervous and Mental Disease. 142(2):101– Walach, H. (2004). Mindfulness-based stress 16. reduction and health beneﬁts. A meta-analysis. 1 35 Delmonte, M. M. (1984). Electrocortical activity Journal of Psychosomatic Research, 57( ), – 43 and related phenomena associated with med- . itation practice: A literature review. Interna- Gunaratana, H. (2002). Mindfulness in plain tional Journal of Neuroscience, 24, 217–231. English. Boston: Wisdom Publications. Delmonte, M. M. (1985). Biochemical indices Gusnard, D. A., & Raichle, M. E. (2001). Search- associated with meditation practice: A lit- ing for a baseline: Functional imaging and the erature review. Neuroscience & Biobehavioral resting human brain. Nature Reviews Neuro- Reviews, 9(4), 557–561. science, 2 (10), 685–694. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

546 the cambridge handbook of consciousness

Holmes, D. S. (1984). Meditation and somatic brain mapping of the relaxation response and arousal reduction. A review of the experimen- meditation. Neuroreport, 11(7), 1581–1585. 1 10 tal evidence. American Psychologist, 39, – . Lazar, S., Kerr, C., Wasserman, R., Gray, J., Jayaraman, K. S. (2003). Technology, tradition Greve, D., Treadway, M., McGarvey, M., unite in India’s drug discovery scheme. Nature Quinn, B., Dusek, J., Benson, H., Rauch, S., Medicine, 9(8), 982. Moore, C., & Fischl, B. (2005). Meditation Kabat-Zinn, J. (2005). Wherever you go, there experience is associated with increased corti- you are: Mindfulness meditation in everyday life. cal thickness. Neuroreport, 16(17):1893–7. New York: Hyperion. Legrand, D. (2005). The bodily self: The sensori- Kabat-Zinn, J., & Chapman-Waldrop, A. (1988). motor roots of pre-reflexive self-consciousness. Compliance with an outpatient stress reduc- Phenomenology and the Cognitive Sciences, 5(1): tion program: Rates and predictors of program 89–118. completion. Journal of Behavioral Medicine, Le Van Quyen, M., Chavez, M., Rudrauf, D., 11(4), 333–352. & Martinerie, J. (2003). Exploring the nonlin- Kabat-Zinn, Lipworth, & Burney (1985). The ear dynamics of the brain. Journal of Physiology, clinical use of mindfulness meditation for the Paris, 97(4–6), 629–639. self-regulation of chronic pain. J Behav Med. Llinas, R., Ribary, U., Contreras, D., & 8(2):163–90. Pedroarena, C. (1998). The neuronal basis for Kabat-Zinn, J., Massion, A. O., Kristeller, J., Peter- consciousness. Philosophical Transactions of the son, L. G., Fletcher, K. E., Pbert, L., Lenderk- Royal Society of London – Series B: Biological ing, W. R., & Santorelli, S. F. (1992). Effec- Sciences, 353(1377), 1841–1849. tiveness of a meditation-based stress reduction Lopes da Silva, F. H., Vos, J. E., Mooibroek, J., program in the treatment of anxiety disorders. & Von Rotterdam, A. (1980). Relative con- American Journal of Psychiatry, 149(7), 936– tributions of intracortical and thalamo-cortical 943. processes in the generation of alpha rhythms, Karma Chagme[´ = Karma-chags-med]. (2000). revealed by partial coherence analysis. Elec- Naked awareness: Practical instructions on the troencephalography and Clinical Neurophysiol- union of Mahamudra and Dzogchen. With com- ogy, 50(5–6), 449–456. mentary by Gyatrul Rinpoche (A. B. Wallace, Lou, H. C., Kjaer, T. W., Friberg, L., Wilds- Trans.). Ithaca, NY: Snow Lion Publications. chiodtz, G., Holm, S., & Nowak, M. (1999). Kasamatsu, A., & Hirai, T. (1966). An elec- A 15O-H2 O PET study of meditation and the troencephalographic study of Zen meditation resting state of normal consciousness. Human (Zazen). Folia Psychiatrica et Neurologica Japon- Brain Mapping, 7(2), 98–105. 315 336 ica, 20, – . Lutz & Davidson 2005. Kiecolt-Glaser, J. K., Glaser, R., Gravenstein, S., Lutz, A., Greischar, L. L., Rawlings, N. B., Ricard, 1996 Malarkey, W. B., & Sheridan, J. ( ). Chronic M., & Davidson, R. J. (2004). Long-term med- stress alters the immune response to influenza itators self-induce high-amplitude gamma syn- virus vaccine in older adults. Proceedings of chrony during mental practice. Proceedings of 7 the National Academy of Sciences USA, 93( ), the National Academy of Sciences USA, 101(46), 3043 3047 – . 16369–16373. 1999 Klimesch, W. ( ). EEG alpha and theta oscil- Lutz, A., Lachaux, J. P., Martinerie, J., & Varela, F. lations reflect cognitive and memory perfor- J. (2002). Guiding the study of brain dynamics mance: A review and analysis. Brain Research – by using first-person data: Synchrony patterns 2 3 169 195 Brain Research Reviews, 29( – ), – . correlate with ongoing conscious states during Lachaux, J. P., Rodriguez, E., Martinerie, J., & a simple visual task. Proceedings of the National Varela, F. J. (1999). Measuring phase synchrony Academy of Sciences USA, 99(3), 1586– in brain signals. Human Brain Mapping, 8(4), 1591. 194 208 – . Lutz, A., Rawlings, N., & Davidson, R. J. (2005). Lack, L. C. (1978). Selective attention and the con- Changes in the tonic high-amplitude gamma oscil- trol of binocular rivalry. Adelaide, The Flinders lations during meditation correlates with long- University of South Australia. term practitioners’ verbal reports. Paper pre- Lazar, S., Bush, G., Gollub, R. L., Fricchione, G. sented at the Society for Neuroscience, Wash- L., Khalsa, G., & Benson, H. (2000). Functional ington, DC. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

meditation and the neuroscience of consciousness 547

Lutz, A., & Thompson, E. (2003). Neuropheno- Nisbett, R. E., & Wilson, T. D. (1977). Telling menology: Integrating subjective experience more than we can know: Verbal reports on and brain dynamics in the neuroscience of mental processes. Psychological Review, 84, 231– consciousness. Journal of Consciousness Studies, 259. 10(9–10), 31–52. Nunez, P. L., Srinivasan, R., Westdorp, A. F., Maguire, E. A., Gadian, D. G., Johnsrude, I. S., Wijesinghe, R. S., Tucker, D. M., Silberstein, Good, C. D., Ashburner, J., Frackowiak, R. S., R. B., & Cadusch, P. J. (1997). EEG coherency. & Frith, C. D. (2000). Navigation-related struc- I: Statistics, reference electrode, volume con- tural change in the hippocampi of taxi drivers duction, Laplacians, cortical imaging, and inter- [see comment]. Proceedings of the National pretation at multiple scales. Electroencephalog- Academy of Sciences USA, 97(8), 4398– raphy & Clinical Neurophysiology, 103(5), 499– 4403. 515. Maguire, E. A., Spiers, H. J., Good, C. D., Nunez, P. L., Wingeier, B. M., & Silberstein, Hartley, T., Frackowiak, R. S., & Burgess, N. R. B. (2001). Spatial-temporal structures of (2003). Navigation expertise and the human human alpha rhythms: Theory, microcurrent hippocampus: A structural brain imaging anal- sources, multiscale measurements, and global ysis. Hippocampus, 13(2), 250–259. binding of local networks. Human Brain Map- Maharishi, M. Y. (1969). Maharishi Mahesh Yogi ping, 13(3), 125–164. on the Bhagavad Gita. New York: Penguin. Ooi, T. L., & He, Z. J. (1999). Binocular rivalry Maturana, H. R., & Varela, F. J. (1980). Autopoiesis and visual awareness: The role of attention. and cognition: The realization of the living, Vol. Perception, 28(5), 551–574. 42. Dordrecht: D. Reidel. Pagano, Rose, Stivers, & Warrenburg, (1976) McClelland, J. L., & Rogers, T.T.(2003). The par- Sleep during transcendental meditation. Sci- allel distributed processing approach to seman- ence. 23;191(4224):308–10. tic cognition. Nature Reviews Neuroscience, Pagano, R. R., & Warrenburg, S. (1983). 4(4), 310–322. Meditation: In search of a unique effect. In R. J. Meaney, M. J. (2001). Maternal care, gene expres- Davidson, G. E. Schwartz, & D. Shapiro (Eds.), sion, and the transmission of individual dif- Consciousness and self-regulation (Vol. 3). New ferences in stress reactivity across generations. York: Plenum Press. Annual Review of Neuroscience, 24, 1161–1192. Panksepp, J. (1988). Affective neuroscience: Merleau-Ponty, M. (1962). Phenomenology of per- The foundations of human and animal ception (C. Smith, Trans.). London: Routledge. emotions.Oxford: Oxford University Press. Miller, G. E., Cohen, S., Pressman, S., Barkin, A., Proudfoot, W. (1985). Religious experience. Rabin, B. S., & Treanor, J. J. (2004). Psycholog- Berkeley: University of California Press. ical stress and antibody response to influenza Rizzuto, D. S., Madsen, J. R., Bromfield, vaccination: When is the critical period for E. B., Schulze-Bonhage, A., Seelig, D., stress, and how does it get inside the body? Aschenbrenner-Scheibe, R., & Kahana, M. J. Psychosomatic Medicine, 66(2), 215–223. (2003). Reset of human neocortical oscillations Morrell, L. K. (1966). Some characteristics during a working memory task. Proceedings of of stimulus-provoked alpha activity. Elec- the National Academy of Sciences USA, 100(13), troencephalography & Clinical Neurophysiology, 7931–7936. 21(6), 552–561. Rosenkranz, M. A., Jackson, D. C., Dalton, K. M., Morse, D. R., Martin, J. S., Furst, M. L., & Dubin, Dolski, I., Ryff, C. D., Singer, B. H., Muller, L. L. (1977). A physiological and subjective D., Kalin, N. H., & Davidson, R. J. (2003). evaluation of meditation, hypnosis, and relax- Affective style and in vivo immune response: ation. Psychosomatic Medicine, 39(5), 304– Neurobehavioral mechanisms. Proceedings of 324. the National Academy of Sciences USA, 100(19), 11148 11152 Newberg, A., Alavi, A., Baime, M., Pour- – . dehnad, M., Santanna, J., & d’Aquili, E. (2001). Saffran, J. R., Aslin, R. N., & Newport, E. The measurement of regional cerebral blood L. (1996). Statistical learning by 8-month-old flow during the complex cognitive task of infants. Science, 274(5294), 1926–1928. meditation: A preliminary SPECT study. Psy- Schiff, S. J., So, P., Chang, T., Burke, R. chiatry Research, 106(2), 113–122. E., & Sauer, T. (1996). Detecting dynamical P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

548 the cambridge handbook of consciousness

interdependence and generalized synchrony perception. Journal of Neuroscience, 19(13), through mutual prediction in a neural ensem- 5435–5448. ble. Physical Review. E. Statistical Physics, Plas- Suffczynski, P., Kalitzin, S., Pfurtscheller, G., & mas, Fluids, and Related Interdisciplinary Topics, Lopes da Silva, F. H. (2001). Computational 54(6), 6708–6724. model of thalamo-cortical networks: Dynami- Schnitzler, A., & Gross, J. (2005). Normal and cal control of alpha rhythms in relation to focal pathological oscillatory communication in the attention. International Journal of Psychophysi- brain. Nature Review Neuroscience, 6(4), 285– ology, 43(1), 25–40. 296 . Takahashi, T., Murata, T., Hamada, T., Omori, Schuman, M. (1980). The psychophysiological M., Kosaka, H., Kikuchi, M., Yoshida, H., & model of meditation and altered states of Wada, Y. (2005). Changes in EEG and auto- consciousness: A critical review. In J. M. David- nomic nervous activity during meditation and son & R. J. Davidson (Eds.), The psychobiology their association with personality traits. Inter- of consciousness, 333–378. New-York: Plenum. national Journal of Psychophysiology, 55(2), 199– Schuster, B. G. (2001). A new integrated program 207. for natural product development and the value Tallon-Baudry, C., & Bertrand, O. (1999). Oscil- of an ethnomedical approach. Journal of Alter- latory gamma activity in humans and its role in native & Complementary Medicine, 7(6), 61– object representation. Trends in Cognitive Sci- 72. ence, 3(4), 151–162. Shapiro, D. H., & Walsh, R. N. (Eds.). (1984). Tebecis, A. K. (1975). A controlled study of the Meditation: Classical and contemporary perspec- EEG during transcendental meditation: Com- tives. New York: Aldine. parison with hypnosis. Folia Psychiatrica et Sharf, R. H. (1998). Experience. In M. Taylor Neurologica Japonica, 29(4), 305–313. 94 (Ed.), Critical terms for religious studies (pp. – Thrangu, & Johnson, C. (2004). Essentials of 116 ). Chicago: University of Chicago Press. Mahamudra: Looking directly at the mind. Sheline, Y. I. (2003). Neuroimaging studies of Boston: Wisdom Publications. mood disorder effects on the brain. Biological Tononi, G., & Edelman, G. M. (1998). Conscious- 3 338 352 Psychiatry, 54( ), – . ness and complexity. Science, 282(5395), 1846– Silananda, U. (1990). The four foundations of mind- 1851. fulness. Boston: Wisdom Publications. Travis, F., Arenander, A., & DuBois, D. (2004). Singer, T., Seymour, B., O’Doherty, J., Kaube, H., Psychological and physiological characteristics Dolan, R. J., & Frith, C. D. (2004). Empathy of a proposed object-referral/self-referral con- for pain involves the affective but not sensory tinuum of self-awareness. Consciousness & Cog- components of pain. Science, 303(5661), 1157– nition, 13(2), 401–420. 1162 . Tsongkhapa [ = Tsong kha pa blo bzang grags pa]. Singer, W. (2001). Consciousness and the binding (2002). The great treatise on the stages of the path problem. Annals of the New York Academy of to enlightenment (31st ed.). Ithaca, NY: Snow Sciences, 929, 123–146. Lion Publications. Singer, W. (1999). Neuronal synchrony: A versa- Urry, H. L., van Reekum, C. M., Johnstone, T., tile code for the deﬁnition of relations? Neuron, Thurow, M. E., Burghy, C. A., Mueller, C. J., 24(1), 49–65, 111–125. & Davidson, R. J. (2003). Neural correlates of Slotnick, S. D., Moo, L. R., Kraut, M. A., voluntarily regulating negative affect. (Report no. Lesser, R. P., & Hart, J., Jr. (2002). Interactions 725.18.). San Diego: Society for Neuroscience. between thalamic and cortical rhythms during Varela, F. (1995). Resonant cell assemblies: A semantic memory recall in human. Proceedings new approach to cognitive functions and neu- of the National Academy of USA, 99(9), 6440– ronal synchrony. Biological Research, 28(1), 81– 6443. 95. Snellgrove, D. L. (2002). Indo-Tibetan Buddhism: Varela, F. (1996). Neurophenomenology: A Indian Buddhists and their Tibetan successors. methodological remedy to the hard problem. Boston: Shambhala. Journal of Consciousness Studies, 3, 330–350. Srinivasan, R., Russell, D. P., Edelman, G. M., & Varela, F. (1999). The specious present: A neu- Tononi, G. (1999). Increased synchronization rophenomenology of time consciousness. In J. of neuromagnetic responses during conscious Petitot, F. J. Varela, J.-M. Roy, & B. Pachoud P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

meditation and the neuroscience of consciousness 549

(Eds.), Naturalizing phenomenology (pp. 266– Warrenburg, Pagano, Woods, & Hlastala, (1980). 314). Stanford, CA: Stanford University A comparison of somatic relaxation and Press. EEG activity in classical progressive relaxation Varela, F., Lachaux, J. P., Rodriguez, E., & Mar- and transcendental meditation. J Behav Med. tinerie, J. (2001). The brainweb: Phase synchro- 3(1):73–93. nization and large-scale integration. Nature Wenger, M. A., & Bagchi, B. K. (1961). Studies of Reviews Neuroscience, 2 (4), 229–239. autonomic functions in practitioners of Yoga in 312 323 Varela, F., & Thompson, E. (2001). Radical India. Behavioral Sciences, 6, – . embodiment: Neural dynamics and conscious- West, M. A. (1980). Meditation and the EEG. ness. Trends in Cognitive Science, 5(10), 418– Psychological Medicine, 10(2), 369–375. 425. West, M. A. (Ed.). (1987). The psychology of med- Varela, F. J., Thompson, E., & Rosch, E. (1991). itation. New York: Clarendon Press. The embodied mind. Cambridge, MA: MIT Wider, K. V. (1997). The bodily basis of conscious- Press. ness. Ithaca, NY: Cornell University Press. von Stein, A., Chiang, C., & Konig, P. (2000). Williams, M. A., Morris, A. P., McGlone, F., Top-down processing mediated by interareal Abbott, D. F., & Mattingley, J. B. (2004). synchronization. Proceedings of the National Amygdala responses to fearful and happy facial Academy of Sciences USA, 97(26), 14748– expressions under conditions of binocular sup- 14753. pression. Journal of Neuroscience, 24(12), 2898– Wallace, A. B. (Ed.). (2003). Buddhism and sci- 2904. ence. New York: Columbia University Press. Williams, P. (1989). Mah¯ay¯ana Buddhism: The Wallace, B. A. (1999). The Buddhist tradition of doctrinal foundations. London: Routledge. Samatha: Methods for reﬁning and examining Woolfolk R. L. (1975). Psychophysiological cor- consciousness. Journal of Consciousness Studies, relates of meditation. Arch Gen Psychiatry. 6(2–3), 175–187. 32(10):1326–33. Wallace, R. K. (1970). Physiological effects of Younger, J., Adriance, W., & Berger, R. J. (1975). transcendental meditation. Science, 167(926), Sleep during Transcendental Meditation. Per- 1751–1754. ceptual & Motor Skills, 40(3), 953–954. Wangchug Dorje[´ = Dbang-phyug-rdo-rje]. Zahavi, D., & Parnas, J. (1998). Phenom- (1989). The Mahamudra eliminating the dark- enal consciousness and self-awareness: A ness of ignorance (3rd rev. ed.). Dharamsala, phenomenological critique of representational India: Library of Tibetan Works and Archives. theory. Journal of Consciousness Studies, 5, 687– Ward, L. M. (2003). Synchronous neural oscilla- 705. tions and cognitive processes. Trends in Cogni- Zeman, A. (2001). Consciousness. Brain, 124(Pt tive Science, 7(12), 553–559. 7), 1263–1289. P1: KAE 0521857430c19 CUFX049/Zelazo 0 521 85743 0 printer: cupusbw November 6, 2006 16:32

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