Psychonomic Bulletin & Review 1999, 6 (3),379-393

Sparkling at the end ofthe tongue: The etiology oftip-of-the-tongue phenomenology

BENNETTL. SCHWARTZ Florida International University, Miami, Florida

The tip-of-the-tongue experience (TOT) is the phenomenological experience that a currently inac­ cessible word is stored in memory and will be retrieved. TOTsappear to be a universal experience that occurs frequently in everyday life, making the TOTan ideal case study in human phenomenology. This paper considers TOTsin light of Tulving's(1989)challenge to the doctrine of concordance, which is the assumption that behavior, cognition, and phenomenology are correlated, if not caused by identical pro­ cesses. Psycholinguistic and memory theories, consistent with concordance, argue for direct access, or the view that TOTsand word retrieval are caused by the same retrieval processes. The metacogni­ tion view challenges concordance and views TOTsas an inference based on nontarget information that is accessible to rememberers. Current data, reviewed here, suggest that TOTsare caused via direct ac­ cess and through inferential processes. Dissociations between TOTs and retrieval suggest that the causes of TOTphenomenology and the processes of retrieval are not identical.

Perhaps the most famous and most quoted passage from regular habits" (p. 215). R. Brown and McNeill developed William James's (1890) Principles ofPsychology is his a methodology for inducing TOTs in a controlled setting. description ofthe tip-of-the-tongue experience (TOT). In They provided students with definitions of difficult the quote, repeated in many cognitive psychology text­ words (e.g., "A place where bees are raised for their books and many papers on the TOT, James writes, honey") and asked the students to provide the word (api­ ary). In some instances, the students experienced TOTs; The state of our consciousness is peculiar. There is a gap therein; but no mere gap. It is a gap that is intensely active. they were sure that they knew the word but were unable A sort of wraith of the name is in it, beckoning us in a to retrieve it. R. Brown and McNeill were also curious given direction, making us at moments tingle with the about what the students could report about the missing sense of our closeness and then letting us sink back with­ target while they were experiencing a TOT. Therefore, out the longed-for term. [f wrong names are proposed to they asked the students to report or guess the first letter us, this singularly definite gap acts immediately so as to ofthe missing target, the last letter ofthe missing target, negate them. They do not fit the mould. And the gap ofone the number ofsyllables, and any words that sounded sim­ word does not feel like the gap of another, all empty of ilar or meant something similar. R. Brown and McNeill's content as both might seem necessarily to be when de­ basic methodology has been employed in almost all scribed as gaps. (p. 251) laboratory-based studies on TOTs ever since. James's description is particularly vivid and accords with Another major landmark in the study ofTOTs was an most people's intuitive experience with TOTs. James's important review paper by A. S. Brown (1991), who sum­ view is based solely on his astute but informal observations marized and organized the relevant research that had been of human thought. The description is so insightful and done on TOTs during the 25-year period after R. Brown complete that it presages modern research on the topic. and McNeill (1966). His paper represents an exhaustive It was not until R. Brown and McNeill's 1966 paper on and thorough review ofthe work on TOTs up to 1991 (for TOTs that empirical research on TOTs began. In a color­ another excellent review, see Smith, 1994). In almost ful description, Jones (1988) reported "Brown and Me­ every section ofthe review, A. S. Brown introduced crit­ Neill showed in their justly famous article that the TOT ical theoretical questions about TOTs that warrant inves­ state, hitherto a feral beast that struck without warning, tigation, but most remain untested. The present paper could be tamed and studied as a creature ofconveniently does not intend to duplicate the coverage ofA. S. Brown. Rather, the paper explores one area ofimportance: the eti­ ology ofTOT phenomenology. The author thanks Alan Brown, Leslie Frazier, Janet Metcalfe, Wai­ The present paper is divided into several sections. First, ter Mischel, Thomas O. Nelson, Endel Tulving, John Wixted, and sev­ I will outline Tulving's (1989) critique ofthe doctrine of eral anonymous reviewers for insightful commentary and discussion on concordance and how it applies to issues of TOT etiol­ preliminary versions of this manuscript. The author also thanks all of ogy. Then, I will outline a number ofmethodological dis­ the informants who contributed to the language survey. Correspon­ dence should be addressed to B. L. Schwartz, Department of Psychol­ tinctions in the empirical study ofTOTs. I will show that ogy, College of Arts and Sciences, Florida International University, many ofthe methodological differences arise from differ­ Miami, FL 33199 (e-mail: [email protected]). ences in assumptions related to the doctrine of concor-

379 Copyright 1999 Psychonomic Society, Inc. 380 SCHWARTZ

dance. In addition, I will make the case that TOTs are ideal fidence, feelings ofknowing, implicit memory, and false case studies in human phenomenology because of their memory) suggest that many researchers no longer rely universality. In the second halfofthe paper, I will review on concordance assumptions. Nonetheless, I will dem­ the major theories ofTOT etiology. I review the evidence onstrate that the assumption is still common in research for direct access and inferential approaches and how they on TOTs. account for the accuracy of TOTs in predicting recall, rec­ In the present paper, I make a logical extension ofTul­ ognition, and knowledge ofpartial information. Finally, ving's critique of the doctrine of concordance. The as­ I conclude with a discussion ofthe role ofTOTs in meta­ sumption made here is that particular cognitive pro­ cognition and suggest some directions for the future. cesses (or mental computation) are responsible both for observed behavior and for phenomenological experi­ THE DOCTRINE OF CONCORDANCE ence. Under the doctrine ofconcordance, the likely sce­ nario is that some cognitive processes produce both the Tulving (1989) expressed dissatisfaction with what he observed behavior and the phenomenology. However, called the doctrine ofconcordance. The doctrine ofcon­ following Tulving's challenge, it is reasonable to postu­ cordance is an implicit assumption in some contempo­ late multiple cognitive processes, some that underlie be­ rary cognitive research, unnamed until Tulving's critique. havior and others that underlie phenomenological expe­ According to the doctrine, cognitive processes, behavior, rience. For example, if a particular cognitive process, such and phenomenological experience are highly correlated. as retrieval, is not always accompanied by the same or any Indeed, Tulving argued that research in cognition has as­ kind ofphenomenological experience, it is likely that the sumed that there is a "general, if not perfect, agreement phenomenological experience has a different underlying between what people know, how they behave, and what mechanism than the cognitive process itself. In some sit­ they experience" (Tulving, 1989, p. 8). In this view, cog­ uations, such as implicit memory tests, retrieval is not nitive processes are the hidden mental computations that accompanied by feelings ofpastness. In other situations, underlie our thought. Behavior is the observable action of course, such as autobiographical memory tests, re­ ofa person. Phenomenological experience is the feeling trieval is accompanied by feelings of pastness. Indeed, that accompanies the cognitive processes and behavior. feelings of pastness are possible without retrieval even In general, Tulving claimed that some psychological re­ taking place (e.g., memory illusions; see Roediger, 1996). search has assumed that behavior, cognition, and phe­ Therefore, it is possible that some cognitive processes pro­ nomenology should and will be closely connected. Tulv­ duce phenomenological experience, whereas other cog­ ing, however, challenged the doctrine by claiming that, nitive processes effect the actual behavioral response. in many cases, there may be dissociations between the Most TOT research implicitly endorses the doctrine. underlying cognitive processes and the phenomenologi­ Contemporary research on TOTs has assumed that cog­ cal experience that accompanies them. nitive processes of retrieval and the phenomenology of In Tulving's view, cognitive psychology's concern with TOTs are the same process. When exceptions to the doc­ the mental computation, or cognitive processes, is not to trine are acknowledged, they have been considered to be be confused with the study ofphenomenological experi­ unimportant (e.g., Astell & Harley, 1996; Perfect & Han­ ence. For example, the cognitive process of"retrieval" is ley, 1992; Rastle & Burke, 1996). There are two major not the same as the experience of "recollection" (Tulv­ consequences of this assumption. First, researchers as­ ing, 1989). For successful recall to occur, the retrieval sume that variables that affect retrieval also affect TOTs. process combines a cue in the environment with an ex­ Therefore, they claim that one can infer the nature ofre­ isting memory trace and elicits a particular response (see trieval by studying TOTs. This principle has guided most Tulving, 1983). The cognitive process ofretrieval results TOT research. Second, until now, most research study­ in mental activity, which may lead to a behavior, such as ing TOTs has implied that phenomenology is redundant articulating the target word. However, this retrieval pro­ with retrieval because both tap the same underlying pro­ cess may not be accompanied by a feeling that recollec­ cesses. Therefore, little research has been directed toward tion from memory has occurred. Words, for example, are TOT phenomenology (but see Schwartz, Travis, Castro, retrieved from memory constantly during speech with­ & Smith, in press). out experiencing recollection. Experienced recollection, I claim that new TOT research refutes the doctrine of or "mental time travel," occurs only in certain retrieval concordance by demonstrating that the processes of re­ situations involving episodic memory. Mental time travel trieval are not always identical to the processes that elicit is the purely subjective experience that accompanies re­ TOTs. There is growing evidence to suggest that the eti­ membering that gives us the feeling of pastness. More­ ology of TOTs differs from the processes that effect re­ over, other nonretrieval factors appear to affect our feel­ trieval, leaving open the possibility for a breakdown in ings of pastness (Jacoby, Kelley, & Dywan, 1989). For concordance. In the course of this paper, I present re­ these reasons, Tulving argued that the doctrine of con­ search from my own laboratory and from others sug­ cordance should no longer be accepted. Clearly, many of gesting that the TOT phenomenology is dissociable from the issues in contemporary cognitive research (overcon- the processes ofword retrieval. TIP OF THE TONGUE 381

TOTS IN THE LABORATORY high feeling of knowing is a matter of degree. In con­ AND EVERYDAY LIFE trast, TOTs "occur involuntarily" and are assessments that "subjects are confident that they can eventually re­ The term TOT has been used in two different contexts, call the target information" (A. S. Brown, 1991, p. 205). which I label first-person and third-person accounts of TOTs and n-TOTs (unrecalled targets for which no TOT TOTs. The first-person, or introspectionist, approach is reported) are qualitatively different states of mind. views TOTs as the feeling oftemporary inaccessibility, A. S. Brown's distinction is typical of the distinction that rather than the objective state oftemporary inaccessibil­ has been made by other researchers who have studied ity (Smith, 1994). That is, TOTs are phenomenological TOTs and feeling of knowing in the same experiment experiences. People, when in a TOT,jeellike they know (e.g., Metcalfe, Schwartz, & Joaquim, 1993; Schwartz, the target word and will remember it eventually. The 1998; Yaniv & Meyer, 1987). word, however, remains inaccessible.' The first-person perspective is more consistent with Tulving's challenge IS THE TOT UNIVERSAL? to the doctrine ofconcordance because it emphasizes the phenomenology. The third-person perspective, by con­ Although the TOT is used here and in the literature to trast, defines TOTs as instances ofword-retrieval failures denote the experience oftemporary inaccessibility, in fact, combined with partial accessibility (Kohn et al., 1987). the term tip ofthe tongue, as a technical psychological That is, a TOT describes the contents ofmemory when a term, is borrowed from colloquial usage. Therefore, in­ known word is not recalled; the feeling ofknowing is not structions to report TOTs are relatively easy to explain to required. According to the third-person perspective, it participants and to be followed by participants. For com­ may not even be necessary to ask the participant whether parison, elaborate instructions are necessary to elicit he or she is experiencing a TOT (e.g., Kohn et al., 1987; remember/know judgments (Gardiner & Java, 1993; Ra­ Vigliocco, Antonini, & Garrett, 1997). Thus, third-person jaram, 1993;Rajaram & Roediger, 1997).Inthe remember/ perspectives are consistent with the doctrine of concor­ know paradigm, instructions and practice must be given dance. To reiterate, in this paper, TOTs are considered to to participants so that they can distinguish between the be first-person phenomenological experiences of remem­ feeling ofrecollection expressed by the "remember"judg­ berers. Gardiner and Java (1993) provided an excellent re­ ment and the feeling of knowledge expressed by the view concerning the differences between first- and third­ "know" judgment. person accounts of subjective aspects of remembering. It is puzzling why people use the metaphor ofthe "tip The "tip ofthe tongue" is a common-language expres­ of the tongue" to describe the experience of temporary sion that is used to describe the experience of the feeling inaccessibility. Does the expression capture the phe­ of knowing that one can recall a word that, in fact, one nomenological experience, or is the expression just a pe­ cannot. The scientific terminology-TOT-is an attempt culiarity ofthe English language (and scientific usage)? to capture and quantify that experience. First-person de­ If the expression captures the experience, one would ex­ finitions given to rememberers in experiments have been pect other languages to use similar metaphors to describe generally consistent from research project to research the feeling. Inorder to answer this question, I conducted project. Most research provides rememberers with a de­ a survey. If terms exist in other languages to express tem­ finition similar to the definition provided by R. Brown porary inaccessibility, but the terms do not use a "tongue" and McNeill (1966). They instructed their participants metaphor, then the phenomenology might vary as a func­ that "ifyou are unable to think the word but feel sure that tion oflanguage spoken. However, ifmost languages use you know it and that it is on the verge ofcoming back to the "tongue-based" metaphor to express temporary inac­ you then you are in a TOT state" (p. 327). These two fea­ cessibility, then that supports the view that TOTs repre­ tures ofthe TOT-inaccessibility and imminence-seem sent universal experience, common to all people. The last to be the key features ofoperational definitions ofTOTs possibility bolsters the argument for using TOTs as a (A. S. Brown, 1991). Forexample, Rastle and Burke (1996) case study in human phenomenology. told participants that they were experiencing a TOT "if I contacted fluent speakers, preferably native, of lan­ they were confident that they knew the word and it was guages other than English. All ofthe people I spoke with on the verge ofcoming back to them" (p. 591). Schwartz were familiar with the English expression "on the tip of and Smith (1997) defined the TOT as "a feeling that you the tongue." I explained to them the definition ofa TOT. can recall the answer. It is the feeling of being on the I reminded them not to simply translate the literal En­ verge of being able to recall the answer that you cannot glish but rather to select the word or expression that de­ recall now" (p. 72). scribed the experience that English speakers capture in TOTs have often been compared and equated to feel­ the expression "on the tip ofthe tongue." ings ofknowing. Although the two are closely related and Across 51 languages known by my informants, 45 lan­ are often highly correlated in empirical work (Schwartz, guages employed an expression that used the "tongue" 1998), they are usually not defined in the same way. A. S. metaphor to express the feeling of not being able to re­ Brown (1991) defines feelings of knowing as assess­ trieve an accessible word (see Appendix A). American ments of recognition that may occur for all unrecalled Sign Language (ASL), Icelandic, two sub-Saharan Afri­ items. Differences between low feeling of knowing and can languages (Kiswahili and Kalenjin), and Indonesian 382 SCHWARTZ

do not use the metaphor of the "tongue" to refer to the the assumptions made concerning the doctrine of con­ TOT.According to my informant, ASL does not have an cordance. It is my intention to alert researchers to the dis­ expression literally meaning "on the tip of the finger." agreements among them concerning their assumptions Five languages (Cantonese Chinese, Mandarin Chinese, about concordance, so that discussion and debate can Hindi, Hausa, and Ibo) use the related expression "in the occur. My goal in this review, by pointing out differences, mouth" to describe the experience. Japanese uses the ex­ is to help synthesize disparate views, not to widen them. pression "out ofthe throat" to describe temporary forget­ ting. Nonetheless, the overwhelming majority of lan­ Psycholinguistics guages use the "tongue" metaphor just as English does. To date, probably the most research concerning TOTs Some languages also use multiple metaphors. For exam­ has come from the psycho linguistic perspective, which ple, Korean uses both the "mouth" and the "tongue" meta­ focuses on TOTs as a temporary breakdown in lexical re­ phor, whereas French speakers use both the "tongue" meta­ trieval (see Burke, MacKay, Worthley, & Wade, 1991). phor and the expression "hole in my head" to express Research from this point ofview has linked TOTs to other temporary forgetting. The survey suggests that the use common errors in spoken language, such as slips ofthe ofthe "tongue" metaphor is not idiomatic to English but tongue and spoonerisms (e.g., saying "toin coss" for rather reflects a common aspect ofTOT phenomenology. "coin toss"). The psycholinguistic perspective tacitly as­ The most common term was an almost literal equiva­ sumes the doctrine of concordance. TOT phenomenol­ lent ofthe English expression "on the tip ofthe tongue" ogy is interesting only to the extent that it tells us some­ (see Appendix B). For example, the expression in Italian thing about lexical retrieval. For this reason, many have is "sulla punta della lingua," and in Afrikaans, "op die made use ofthird-person TOTs as a "window" on word punt van my tong," which both translate as "on the retrieval (Kohn et al., 1987; Vigliocco et al., 1997). tip/point ofthe tongue." Other languages use slight vari­ By studying what speakers know and can say when they ants. For example, Estonian ("keele otsa peal") translates are experiencing a TOT, psycholinguists can infer the to "at the head of the tongue," whereas Cheyenne ("na­ multidimensional nature ofwords and the potential dis­ vonotootsea") translates as "I have lost it on my tongue." sociation between a word's phonological, semantic, and Irish ("ar flaen fy nhafod") refers to the "front of the lexical components. Rastle and Burke (1996), for exam­ tongue," whereas Welsh ("ar bharr theanga agam") trans­ ple, wrote that "ifthere is sufficient semantic priming to lates to "on the top of my tongue." Marathi ("jeebhe­ activate the correct lexical node, but there is a deficit in war") simply uses "on the tongue." Perhaps the most po­ phonological activation, a TOT response will be produced. etic is Korean, in which the expression ("Hyeu kkedu-te Thus, TOTs provide a means of isolating phonological mam-dol-da") means "sparkling at the end ofmy tongue,'? processes within a conceptually-driven task" (p. 594). The general similarity of the expressions, however, does Astell and Harley (1996) wrote that "the study of TOTs suggest that the "tongue" metaphor captures a common shed light on the processes ofword selection and retrieval, phenomenology across languages. both components oflexicalization in speech production" Study ofTOTs gives us an empirical "lens" on the na­ (p. 196). Meyer and Bock (1992) added that "the familiar ture ofphenomenological experience. Certain character­ tip-of-the-tongue (TOT) experience suggests that recov­ istics of TOTs make them useful to develop theories of ering a word from the mentaI.Iexicon involves something phenomenology and experience. For example, TOTs ap­ more than a single, simple, look-up" (p. 715). Thus, the pear to be common in everyday life, they are easy to in­ emphasis in this approach is what TOTs can tell us about duce in the lab, and they appear to be quite similar across lexical retrieval. language groups. Furthermore, although TOTs are phe­ nomenological experiences, which only the rememberer is aware of, TOTs are linked to a specific objective be­ Memory Perspectives havior-namely, the attempts made to retrieve particular The memory-oriented perspective to TOTs, like the target words. Thus, the phenomenology can be directly psycholinguistic approach, assumes the doctrine ofcon­ compared to behavioral indices. Because of these fea­ cordance. Researchers interested in memory have ap­ tures, TOTs offer us the opportunity to test theories con­ proached TOTs as a marker of retrieval processes gone cerning human phenomenology. Inthe following section, awry. Indeed, A. S. Brown (1991) suggests that TOTs of­ I address why most TOT studies have been more con­ fer us an opportunity to study retrieval similar to "slow­ cerned about the state ofknowledge during a TOT than motion photography." During a TOT, a known word can­ in the TOT phenomenology itself. not be recalled but is stored in memory. The memory approach has shared concerns with the psycholinguistic THE TOT IN DIFFERENT SUBDISCIPLINES perspective-namely, an emphasis on the kinds ofinfor­ mation that are accessible when a person is in a TOT and Most research on TOTs has been guided by psycho­ how TOTs are eventually resolved. Memory researchers linguistic, memory, or metacognitive approaches. Al­ emphasize, however, the process ofretrieval and the na­ though these approaches can be grouped under a general ture ofmnemonic cues. Smith (1994) wrote that "from a rubric of cognitive psychology, the approaches differ in theoretical point of view, the TOT experience may be a TIP OF THE TONGUE 383

key phenomenon for understanding memory retrieval Other Approaches (p. 28). Others are more concerned with what the TOT Three other approaches are grouped together because can tell us about the nature oftemporary forgetting, such research within these traditions is sparse and mostly draws as Anderson and Neely (1996), who consider TOTs to in­ on either the psycholinguistic model or the memory model. dicate interference in memory. They write that "the clear­ I included them here for completeness. However,through­ est examples ofthis experience [interference] occur dur­ out the rest of this article, I will only refer to this work inas­ ing tip-of-the-tongue states, in which our ability to name much as the papers reviewed here overlap with the psycho­ a particular person, place, or object seems thwarted by a linguistic, memory, or metacognitive perspectives. persistently intrusive word" (p. 248). Thus, like the psy­ The everyday-ecological approach (e.g., Read & Bruce, cholinguistic view, the memory view also implicitly en­ 1982; Reason & Lucas, 1984) has considered TOTs to dorses the doctrine of concordance because of its equa­ be an important topic because TOTs are "inherently inter­ tion of TOTs with the retrieval process. esting" to both researchers and laypeople (A. S. Brown, 1991). Everyday approaches have often stressed "diary" Metacognitive Approach studies in which people record naturally occurring TOTs Metacognitive models emphasize the role that moni­ in their daily lives (Burke et al., 1991; Reason & Lucas, toring and controlling processes play in cognition (e.g., 1984). Retrospective questionnaires are also used in this Bjork, 1994; Metcalfe, 1993; Nelson, 1996; Nelson & approach (Burke et aI., 1991). These studies reveal that Narens, 1990, 1994). In these models, metacognitive pro­ TOTs are common experiences; most people experience cesses are separate from the cognition that they monitor one at least once during any given week (Burke et al., and control. Typically, one process, considered the ob­ 1991). Moreover, most people usually report being able ject-level process, carries out the behavior, whether it is to resolve them (i.e., eventually recall the missing target) learning, remembering, or problem solving. The second, ifgiven enough time. or meta-level process, monitors the object-level process, Developmental approaches have examined TOTs in often with the goal ofeffectively controlling the object­ children and in older adults. Two studies have looked at level process (see, e.g., Nelson & Narens, 1990). Meta­ TOTs in young children (Elbers, 1985; Wellman, 1977). cognitive models, therefore, do not assume the doctrine Cognitive gerontology has maintained an interest in TOTs of concordance because it is possible that phenomenol­ because across many studies, it has been demonstrated ogy is a function ofthe metacognitive process rather than that older people experience more TOTsthan younger peo­ the ongoing cognitive processes. Although Nelson and ple (A. S. Brown & Nix, 1996; Burke et al., 1991; Finley Narens's model does not specifically discuss TOTs, the & Sharp, 1989; Maylor, 1990; Rastle & Burke, 1996). current adaptation of the model suggests that TOTs are Neuropsychological approaches have looked at TOTs in phenomenological consequences of a monitoring pro­ patient populations, such as patients with Alzheimer's cess that indicates that an unrecalled word may be known. disease (Astell & Harley, 1996), patients with Parkin­ The monitoring process that elicits TOTs is separable son's disease (Matison, Mayeux, Rosen, & Fahn, 1982), from the cognitive process that effects retrieval. and aphasics (Bruce & Howard, 1988; Funnell, Met­ The metacognitive model lends itself to the study of calfe, & Tsapkani, 1996; Vigliocco, Vinson, Martin, & the phenomenology of TOTs. Smith (1994) wrote that Garrett, 1999). This area holds considerable promise, "in the course ofrecalling names or words, people some­ but the research remains inchoate. times find themselves in a 'tip-of-the-tongue' state, a dis­ To summarize, most research on TOTs has assumed comfiting experience in which a seemingly well-known the doctrine of concordance. The exception is research mo­ term appears to be blocked from conscious awareness" tivated by metacognitive models. Metacognitive models (p. 27). Note, in this quote, that the emphasis is on the feel assume that TOTs are the output ofa monitoring system ofthe TOT In fact, Schwartz et al. (in press) found that separable from the retrieval process. Therefore, the meta­ TOTs could be divided into substates, depending on their cognitive model leads to greater attention to the relation phenomenological status. They found that rememberers between TOTs and retrieval (e.g., accuracy) and to the could distinguish between strong and weak TOTs, emo­ phenomenology ofthe TOT itself. tional and nonemotional TOTs, and imminent and non­ imminent TOTs. THEORIES OF TOT Another aspect of TOTs that is emphasized in the meta­ cognitive model is why TOTs are accurate predictors of In this section, the major contemporary cognitive the­ performance. Because the process of retrieval and the ories concerning the etiology of TOTs will be consid­ process that produces TOTs are thought to be different, the ered. Each theory will be discussed with regard to the reason why they are so highly correlated becomes an im­ data that support it and its relation to the doctrine ofcon­ portant question. Therefore, consideration of how and cordance. Nelson, Gerler, and Narens (1984) categorized when TOTs are predictive of future performance is im­ theories concerning the bases of metamemory into two portant because the monitoring that produces the TOTs main classes (for a more recent review, see Schwartz, may not always be accurate. 1994). Recently, these' classes have been applied to TOTs 384 SCHWARTZ

(Metcalfe et al., 1993; Schwartz & Smith, 1997; Smith, (Burke et al., 1991). This remarkably high percentage 1994). The two classes of theories were labeled direct­ seems to indicate a high correspondence between TOT access views and inferential views. Direct-access views phenomenology and objective performance. However, argue that TOTs arise from sensitivity to the unretrieved Burke et al. included "consulting a person or book" target.Although items have insufficient memory "strength" (p. 553) as successful resolution, and this may inflate res­ to be recalled, they are strong enough to signal TOTs. In­ olution rates. Furthermore, participants may be more in­ ferential views claim that TOTs are not based directly on clined to report resolved TOTs than unresolved TOTs. an inaccessible but activated target. Rather, TOTs arise Another problem with diary studies is that resolution from clues that the rememberer can piece together. These rates cannot be determined for n-TOTs (unrecalled items clues are information that is accessible to the remern­ that are not accompanied by TOTs). Thus, one cannot berer, such as information from the retrieval cue or in­ compare resolution rates for unrecalled words that are formation related to the target that is retrieved. Although not accompanied by TOTs. Thus, laboratory studies may direct-access and inferential views are not mutually ex­ provide a better index of the accuracy of TOTs at predict­ clusive, they represent very different approaches to the ing resolution. etiology ofTOTs, and have led to different research em­ In the laboratory, resolution rates with definitions phases. The two classes of theories differ with respect to or general-information questions are typically around their position on the doctrine of concordance. Direct-ac­ 40% (A. S. Brown, 1991). Resolution is even lower with cess views typically implicitly endorse concordance, episodic-memory stimuli (Ryan, Petty, & Wenzlaff, 1982; whereas inferential views usually challenge the doctrine. Schwartz, 1998). Typically, however, laboratory data are based on studies that investigate immediate resolution, Direct-Access Views whereas diary studies tap both immediate and delayed Direct-access approaches fall into three basic views. resolution. Indeed, Smith (1994) found that immediate The first view, the blocking hypothesis (i.e., Jones, 1989), resolution ofTOTs for fictional animals was 9%. Reso­ contends that TOTs occur when a retrieval cue prompts lution rose to 43% after a 6-min delay. Furthermore, retrieval ofan incorrect but closely related word. The re­ Smith found that resolution was much more likely to alization that the retrieved word is incorrect prompts the occur after a TOT than after an n-TOT (an item not re­ experience ofthe TOT. The second view, the incomplete called that does not produce a TOT). Resolution rates for activation hypothesis, states that the TOT occurs when n-TOTs were 3% at the immediate test and 19% at the rememberers cannot recall the target word but sense its delayed test. Schwartz (1998) also found lower resolu­ presence nonetheless. The third direct-access view has tion rates for n-TOTs. These studies demonstrate a strong been developed by Burke and her colleagues (Burke et aI., correspondence between TOTs and the likelihood ofsuc­ 1991; Rastle & Burke, 1996; see also Harley & Bown, cessful resolutions, which supports the view that TOTs 1998).Burke's view, the transmission deficit model, argues reflect target retrieval processes. that TOTs arise from a multicomponent memory repre­ Recognition ofTOT targets. Although an item may sentation. TOTs occur when there is activation ofthe se­ not be strong enough to be recalled, it may exist in mem­ mantic component ofthe word, but priming does not pass ory and may be accurately recognized. For this reason, a to the phonological level of the word. For example, on recognition test can assess whether the TOT items are ac­ hearing the definition, "a device for protection from the tually ofhigher activation than items not in a TOT. Some rain or sun," a semantic and perhaps a visual representa­ TOT studies have looked at recognition of targets after tion ofthe object may be retrieved, but the definition does the rememberers experienced TOTs and when they did not activate the phonological representation (e.g., the not (e.g., Burke et aI., 1991; Kozlowski, 1977; Schwartz, word umbrella). 1998; Schwartz & Smith, 1997; Schwartz et aI., in press; Smith, Balfour, & 1. M. Brown, 1994; Widner, Smith, & Support for the Direct-Access View Graziano, 1996). Recognition of the correct target fol­ Support for the view that TOTs are a product arising lowing a TOT is far greater than recognition ofthe cor­ from the same processes that support retrieval will be re­ rect target when rememberers are not experiencing a viewed in this section. Three basic kinds of evidence TOT (see Table I). Schwartz (1998) measured the gamma have been used to support direct access: resolution and correlation between TOTs and recognition, finding a recognition ofTOT targets, and retrieval ofpartial infor­ correlation of.66 between TOTs and correct recognition mation. Each methodology reveals strong associations (see Nelson, 1984, for discussion ofthe gamma correla­ between TOTs and retrieval. The evidence reviewed here tion). Thus, like resolution, studies that examine recog­ supports each ofthe three different direct-access views. nition also find strong correlations between the presence Resolution ofTOT targets. Support for the assump­ ofTOTs and the likelihood ofcorrect target retrieval. tion that TOTs arise from retrieval processes comes from Partial information of TOT targets. A. S. Brown studies that find strong positive correlations between the (1991) provided a thorough review ofthis literature that likelihood of experiencing a TOT and the likelihood of 1will not attempt to duplicate but will briefly summarize resolving the target. Resolution is the uncued retrieval of and update. In partial information reports, the remem­ a previously unrecalled TOT item. In one diary study, 96% berers are asked to recall specific aspects of the target of recorded TOTs were reported as eventually resolved word. Usually, this involves phonological information, TIP OF THE TONGUE 385

Table 1 to categorize them as mass or count better than chance Percent Correct on Recognition Tests as a when in a TOT. Function of Phenomenological State, TOT and TOTs have been shown to be accurate predictors ofob­ n-TOT (Items Not Recalled and Not in TOT) jective memory performance. Moreover, when remem­ Study TOT n-TOT berers are experiencing TOTs, they often successfully re­ Burke et al. (1991) 81 not reported call partial information about the target This suggests Kozlowski (1977) 73 46 Schwartz (1998) that people experiencing TOTs are retrieving target infor­ Experiment I 81 63 mation. Therefore, these phenomena are consistent with Experiment 2 40 II the position that the retrieval process is causing the TOT Schwartz & Smith (1997) for the unrecalled word. Thus, these findings support the Experiment I 81 70 Experiment 2 83 74 view that TOTs reflect target word activation. Moreover, Experiment 3 84 64 because ofthe strong correlation between TOTs and as­ Schwartz et al. (in press) pects of target retrieval, they offer support for the doc­ Experiment I 33 10 trine ofconcordance as well. Experiment 2 35 10 To summarize, a large database exists demonstrating Experiment 3 32 10 Smith et al. (1994) 78 57 a strong correlation between TOTs and the likelihood of Note-Higher recognition performance for TOTs than for n-TOTs in­ resolution, recognition, and retrieval ofpartial informa­ dicates accurate performance. tion. This strong correlation is suggestive, but not con­ clusive, ofdirect-access mechanisms. Indeed, inferential mechanisms can also account for these correlations (i.e., such as the first letter, the number of syllables, and the Koriat, 1993). Nonetheless, I have included them in this syllabic stress (R. Brown & McNeill, 1966; Rubin, 1975). section because of general acceptance that the accessi­ Participants may also be asked whether they can retrieve bility ofpartial information and the eventual retrieval of words that sound similar to or mean something similar to TOTs support direct-access mechanism (i.e., A. S. Brown, the TOT target The rationale for this kind of report is 1991; Vigliocco et al., 1997). the assumption that the TOT reflects activation ofa tar­ Direct-access approaches divide into three separate get word but insufficient activation to achieve recall. Yet views: the blocking hypothesis, the incomplete activa­ there may be enough activation to allow for partial re­ tion hypothesis, and the two-stage transmission deficit call. Indeed, almost all studies that elicit partial informa­ model (Burke et al., 1991). Although all three hypotheses tion find that participants can accurately retrieve some agree that TOTs arise from access to an unretrieved tar­ partial information. TOTs have been shown to be corre­ get, each postulates a different mechanism. I now exam­ lated with knowledge of first letters, last letters, number ine each ofthese three specific theories in greater detail. of syllables, knowledge of similar words, and syllabic stress (see A S. Brown, 1991). Koriat and Lieblich (1974) Blocking Hypothesis showed that more partial information was retrieved when The blocking hypothesis states that TOTs occur be­ rememberers were in TOTs than could be explained by a cause rememberers retrieve target words related to the normative guessing strategy. This is not limited to En­ correct target but are recognized by the rememberers as glish. Murakami (1980) found partial recall ofletters in being incorrect (Jones, 1989). According to the blocking Japanese, and Bak (1987) found partial recall offirst let­ hypothesis, TOTs occur because the rememberers rec­ ters in Polish. Bak also documented that Polish rernern­ ognize blockers as incorrect but cannot retrieve the cor­ berers were able to retrieve words that sounded similar to rect but inhibited target. A S. Brown (1991) wrote, "the or meant something similar to the TOT word. blocking perspective suggests that the TOT represents a More recent studies have examined the relation be­ memory search that has become sidetracked" (p. 215). tween TOTs and syntactical features of language. Ital­ The incorrect intruders that sidetrack retrieval have been ian-speaking rememberers have access to the gender of labeled as blockers (Reason & Lucas, 1984), interlopers words when in a TOT (Miozzo & Caramazza, 1997; Vig­ (Jones, 1989; Jones & Langford, 1987), and related words liocco et al., 1997). Iwasaki, Vigliocco, and Garrett (in (A. S. Brown, 1991). The hypothesis suggests that vari­ press) found that Japanese rememberers had access to ables that increase the retrieval ofthese blockers will both parts ofspeech, such as whether a word was an adjective inhibit correct recall and promote TOTs. or an adjectival noun, when in a TOT. Furthermore, Like other direct-access models, the blocking hypoth­ Vigliocco et al. (1999) found that English-speaking par­ esis easily accounts for why TOTs accurately predict ticipants have access to the type of article used for memory performance. Accuracy is ensured because TOTs "mass" (i.e., some) or "count" (i.e., the) nouns when in are caused by activation of target memories. Because a TOT. For example, the words water and asparagus are TOTs are caused by activation ofthe sought-for word, a never pluralized; we indicate quantity by terms such as change in retrieval conditions may remove the processes more, some, and less. These are considered mass nouns. that are inhibiting retrieval, Retrieval may be inhibited by Count nouns, such as cucumber and photograph, are plu­ blockers, but the blockers are recognized as incorrect. ralized by adding an s. In the absence ofbeing able to re­ Once the inhibition is removed by a change in retrieval call the target word, rememberers are nonetheless able cues or the forgetting ofthe blocker, TOTs will be resolved. 386 SCHWARTZ

Evidence concerning blocking. The blocking hy­ ate experimentally because it is not clear whether the pothesis suggests that the rememberers retrieve words or experimenter-provided blockers serve as blocker or re­ blockers that are recognized as incorrect but that inter­ trieval cues. Furthermore, it is also unclear whether the fere with correct retrieval. Empirically, however, this is experimenter-provided blockers actually mimic the role difficult to measure. In fact, most ofthe research directed ofblocking in retrieval and TOT etiology. Therefore, de­ at blocking has provided words or blockers thought to be spite the mixed evidence on blocking, it should remain a capable of providing interference and has examined viable hypothesis. Indeed, it is a hypothesis waiting for whether these words induce TOTs. a better, as yet undiscovered, methodology. Jones and his colleagues (Jones, 1989; Jones & Lang­ ford, 1987) used experimenter-provided blockers to ex­ Incomplete Activation amine the blocking hypothesis. Participants were pre­ The incomplete activation theory states that TOTs are sented with the definitions of difficult words and were caused by sensitivity to the existence of an unrecalled asked to retrieve a target word. For some of the items target in memory, accompanied by the failure to retrieve (banal), Jones presented a word that was semantically the target into conscious memory. In an incomplete acti­ related (uninspired) to the target word along with the de­ vation model (R. Brown & McNeill, 1966), TOTs occur finition. For other items (bibliophile), Jones presented a because a target word is strong enough to induce a TOT word that was phonologically related (buffoonery). If but not strong enough to elicit recall. Incomplete activa­ blocking is crucial to TOTs, then presenting a potential tion invokes a direct-access mechanism to account for blocker should increase the likelihood that the partici­ TOTs, which are simply intermediate states ofknowledge. pants report a TOT. In fact, semantic blockers did not in­ In incomplete activation, the accuracy with which crease the likelihood ofa TOT, but phonological block­ TOTs predict memory performance is straightforward. ers did. Jones, however, did not counterbalance the target TOTs should occur only for target words that are present words from the semantic, phonological, and control con­ in memory because TOTs represent intermediate mem­ dition, and the results were actually a function ofthe par­ ory strengths. Because accessibility may fluctuate due to ticular words that were in each condition (see Meyer & transitory factors, an item that is currently inaccessible, Bock, 1992; Perfect & Hanley, 1992). When materials but in a TOT, may fluctuate to higher accessibility or were counterbalanced, Meyer and Bock (1992) found that strength and then be resolved. Because TOTs represent the condition that led to the highest reported TOT levels, higher activation than unrecalled items not in a TOT, TOT the phonological cuing condition, actually led to the high­ targets will be more likely to be recognized. Incomplete est number of correct responses, but there were no dif­ activation theory is also consistent with the doctrine of ferences in number ofreported TOTs. Moreover, Perfect concordance, since the phenomenology of TOTs arises and Hanley (1992) included a control condition in which from the strength ofa memory trace. the same stimuli that Jones used were shown without the presence ofthe blocking words. Perfect and Hanley found Transmission Deficit Model that the words that Jones (1989) had used in the phono­ In the transmission deficit model (Burke et al., 1991; logical blocking condition resulted in more TOTs even Rastle & Burke, 1996), TOTs are induced whenever the when no blocking words were included. Perfect and Han­ semantic representation of a word is activated, but the ley, like Meyer and Bock, argued against any role for activation fails to prime the complete phonological rep­ blocking in the etiology ofTOTs. resentation of the target word (see Figure I). The trans­ Smith (1994) did find evidence that supports the block­ mission deficit model differs from the incomplete acti­ ing view using episodic-memory stimuli. Rememberers vation model because it assumes two separate target learned the names offictional animals. Later, at test, they representations: semantic and phonological. For this rea­ were presented with the picture ofthe animal, along with son, Harley and Bown (1998) label the transmission def­ a word that was phonologically similar to the name, the icit model a two-stage model of TOTs and label the in­ name ofanother animal, or a word that was unrelated to complete activation model a one-stage model. the target name. Smith found that the phonologically sim­ Burke et al. (1991) wrote that the "basic cause ofTOTs ilar items increased recall, relative to the control, with­ in the NST [transmission deficit model] is a deficit in out increasing the reported number ofTOTs. The seman­ the transmission of priming across critical connections tically similar cues increased both recall and TOTs. This required for producing the target word" (p. 545). There­ pattern ofresults is consistent with the blocking hypoth­ fore, although the model requires a dual representation esis. Semantically similar items caused participants to ofthe target, TOTs arise from direct access to these par­ think the items were recallable. It is not clear, however, ticular representations and via the same process that is used whether the TOTs resulted from blocking of target re­ in retrieval. Because a single process elicits both retrieval trieval with misleading information or the TOTs were in­ and the TOT phenomenology, the transmission deficit duced because semantically similar items serve as sub­ model implicitly endorses the doctrine ofconcordance. jectively better cues (see Cue Familiarity section below). The explanation for the accuracy with which TOTs Blocking theory states that the rememberers retrieve predict later memory performance is similar to the ac­ blockers, and these interfere with retrieval of the cor­ count ofaccuracy discussed in the Incomplete Activation rect target. The blocking hypothesis is difficult to evalu- section. When a word definition is given, the semantic rep- TIP OF THE TONGUE 387

SEMANTIC SYSTEM

used for type of is a b~ng B Pqr )51 Semantic Nodes

(TOT target) (prime)9hist papyrus pagoda

Lexical Nodes PHONOLOGICAL SYSTEM

Phonological Nodes

p

Figure I. Burke et al.'s transmission deficit model. From "On the Tip ofthe Tongue: What causes word find­ ing failures in young and older adults?" by D. M. Burke, D. G. MacKay, J. S. Worthley, and E. Wade, 1991, Jour­ nal ofMemory and Language, 30, p, 544. Copyright 1991 by Academic Press. Reprinted with permission. resentation ofthe target word is activated. Priming spreads icit model because the priming increases the level of to an existing phonological representation. Changes in phonological activation, which then makes the target retrieval conditions will lead to changes in activation and word more accessible. priming, which may result in resolution ofTOTs. Harley and Bown (1998) have also found results that The model makes some specific predictions concern­ are consistent with a two-stage model of TOTs, similar ing the likelihood of TOTs. First, connections between to Burke et al.s (1991) transmission deficit model. Har­ the semantic and phonological levels become stronger ley and Bown varied the frequency of words and the num­ with greater use. Therefore, less frequently used words ber oflexical neighbors (i.e., closely related phonological (e.g., kiosk, sump) should give rise to more TOTs than words). They found that TOTs were more likely for low­ common words (e.g., house, girl). Second, recency of use frequency words than for high- frequency words and that strengthens connections. Words that have not been en­ TOTs were more likely for those items with fewer close countered recently should be more likely to induce TOTs phonological neighbors. Both effects are consistent with than less recently encountered words. Third, aging also a view that TOTs are the result of a breakdown between weakens connections between the semantic and phono­ phonological and semantic representations. logical levels. Therefore, older people should experience One methodological problem clouds the interpretation more TOTs than younger people. In a series of studies, of data from Rastle and Burke (1996) and Harley and including both diary studies and experimental techniques, Bown (1998). In both studies, the interest was in the ef­ Burke et al. (1991) found support for all three of these fect of manipulated experimental variables on both re­ hypotheses. Rastle and Burke (1996) examined the effect call and the number ofTOTs. Because TOTs can only be of semantic and phonological priming of the target on made on those items not originally recalled, measured the likelihood of TOTs in a general-information paradigm. recall and TOTs are not independent of each other. If They found that phonological priming increased the there are differences in recall, the subset of items for number of correct responses and decreased the number which TOTs can be given may be different. If an experi­ of TOTs. Semantic priming had no additional effects. mental variable, such as the phonological priming vari­ Rastle and Burke argue that the lowering of TOT rates able in the Rastle and Burke experiments, increases re­ via phonological priming supports the transmission def- call, then it decreases the set of items on which TOT 388 SCHWARTZ

judgments can be made. Thus, in the Rastle and Burke cues are familiar and considerable related information is study, it is possible that the unrecalled words in the phono­ retrieved, the rememberers will usually have a represen­ logical primed condition represented a harder set ofitems tation ofthe target word in memory. Unfamiliar cues that than the unrecalled unprimed words. Thus, the lower rate do not elicit related information are, correspondingly, of TOTs may be a function of the more difficult items less likely to induce TOTs, but it is also likely that the re­ and not the manipulated variable (see Schwartz & Met­ memberers will not have the target representation. In this calfe, 1994). When evaluating etiologic issues in TOTs, way, TOTs are thought to be a product of a heuristic. The it important to equate recall or recognition across exper­ experience of a TOT generally means that target retrieval imental conditions. is likely; however, because the TOT is not based on tar­ The transmission deficit model can account for much get retrieval, occasions will arise when a TOT is elicited ofthe data on TOTs. It succinctly accounts for frequency by certain factors when no representation ofthe target is effects, neighborhood effects, phonological priming, the present. Thus, inferential mechanisms can also account accessibility of partial information, and differences in for the high correlation between resolution, recognition, TOTs between younger and older rememberers. How­ and access to partial information, if we assume that the ever, it cannot explain some of the data, such as cue processes that cause TOTs are correlated to the pro­ priming, which provide support for inferential theories cesses that evoke retrieval. and challenge the doctrine ofconcordance. Therefore, it There are two main hypotheses within the inferential is likely that any adequate explanation ofTOIs will need framework. Like the difference between direct access to include a mechanism similar to the transmission def­ and inferential in general, these two hypotheses are not icit model or another direct-access mechanism with a mutually exclusive. Cue familiarity theory suggests that mechanism that produces TOTs inferentially. some TOTs arise because of a strong feeling elicited by recognizing a familiar cue (Metcalfe et aI., 1993). Koriat's Inferential Views (1993, 1995) accessibility heuristic argues that TOTs may In the inferential approach, the TOTs are not based on arise from inferences made on the basis of the amount sensitivity to inaccessible but activated targets. Instead, and kind of information retrieved from memory when rememberers infer the target's existence from clues that the target is not recalled. In the next two sections, I con­ inform us that it is likely to be in memory. The clues that sider the evidence for each ofthese views. are used to make the inference may include the cue (e.g., Metcalfe et aI., 1993), retrieved partial information about Cue Familiarity the target (Koriat, 1993), or any generated information The cue familiarity hypothesis states that TOTs are related to the target name (Schwartz & Smith, 1997). based on an assessment of the level of recognition of a Cues can be considered anything in the environment that particular cue or question (Metcalfe et aI., 1993). This may help the rememberers retrieve the sought-for target. approach dismisses the relevance ofthe unretrieved tar­ Generated information may consist ofbits and fragments get altogether and instead emphasizes the role of the cue. ofthe sought-for target or may consist ofwords, pictures, In its purest form, the cue familiarity hypothesis suggests and other kinds ofinformation that are related to the tar­ that a familiar cue should induce a TOT regardless of get. Inferential approaches to metacognition have been whether or not the target is known. There is a large data­ shown to be useful in explaining the bases ofseveral dif­ base describing the importance of cue familiarity in ferent metacognitive judgments, including speeded feel­ feeling-of-knowing judgments (Connor, Balota, & Neely, ing of knowing (Reder, 1987; Reder & Ritter, 1992), 1992; Metcalfe, 1993; Metcalfe et aI., 1993; Reder, 1987; slower feeling-of-knowing judgments (Koriat, 1993; Reder & Ritter, 1992; Schwartz & Metcalfe, 1992). How­ Metcalfe, 1993; Metcalfe et aI., 1993; Schwartz, 1994; ever, less data exist linking cue familiarity with TOTs. Schwartz & Metcalfe, 1992), and judgments oflearning Koriat and Lieblich (1977) examined the relation be­ (Benjamin, Bjork, & Schwartz, 1998; Koriat, 1997). In­ tween TOTs and the cues or questions that elicited the ferential explanations, developed within a metacognitive TOTs. They labeled the questions as pointers because perspective, are inconsistent with the doctrine ofconcor­ they "point" or cue the relevant target answer. Koriat and dance. The inferential approach assumes that TOTs are Lieblich analyzed the pointers along several dimensions, caused by a process other than the retrieval process. but the most relevant finding is that question redundancy Therefore, consistent with Tulving (1989), the phenom­ led to more TOTs for unrecalled items than more suc­ enology of TOTs is elicited by one process, and target cinct definitions. For example, definitions with repetitive retrieval occurs by another. elements, such as "a circle, or any indication of radiant Unlike the straightforward manner in which direct­ light, around the heads ofdivinities, saints, sovereigns in access views account for the accuracy with which TOTs pictures, medal, etc." (nimbus) tended to produce more predict recognition, the inferential account of accuracy TOTs than did more concise definitions, such as "the sci­ requires an additional step. The inferential view claims that ence of coins" (numismatics). This trend toward more the processes that produce TOTs and the processes that TOTs in questions with repetitive elements in the cue effect target retrieval are generally correlated. Thus, when was the same across TOTs that were resolved (i.e., even- TIP OF THE TONGUE 389

tually recalled or recognized) and those that were not. ipants were given the country name as a cue for the re­ Thus, Koriat and Lieblich's results suggest that cue fac­ trieval of the animal name. If the participants could not tors playa role in causing TOTs. retrieve the name ofthe animal associated to a given coun­ Metcalfe et al. (1993) directly tested the roles of cue­ try cue, they were then asked for a TOT judgment and based sources in TOTs in an episodic-memory paradigm. asked to guess at the first letter ofthe animal's name. The Participants studied cue-target word pairs. In one condi­ participants were also asked to retrieve as much related tion, both the cue and the target were repeated (A-B information as they could. Related information included A-B). In a second condition, the cue was repeated, but both biographical information and descriptions of the with a new unrelated target (A-B A-D). In a third con­ appearance ofthe animal. dition, neither the cue nor the target was repeated (A-B The encoding manipulation did not affect recall ofan­ C-D). In accordance with results from interference par­ imal names, nor did it affect the recognition ofunrecalled adigms, Metcalfe et al. found that the A-B A-D condition names. Thus, the set ofitems on which TOTs were to be showed the lowest recall. Recall was highest in the A-B made was equated. However, consistent with Koriat's A-B condition, presumably because both cue and target (1993, 1995) accessibility theory, there were more TOTs are repeated. If TOTs are based on the strength of the reported in the medium and maximum information con­ representation, as predicted by incomplete activation, the ditions (19%) than in the minimum information condition A-B A-B condition should show the highest number of (11%). Moreover, the number ofreported TOTs was cor­ TOTs.3 Cue familiarity, however, predicts that because related with the amount ofrelated information retrieved. the cue is repeated in both conditions (A-B A-B and Thus, when more information was accessible to partici­ A-B A-D), TOTs will be high for each when compared pants, they were more likely to experience TOTs. with the condition in which the cue is presented only once The accessibility framework offered by Koriat offers (A-B C-D). Indeed, Metcalfe et al. found that the repe­ an alternative explanation for the findings linking the re­ tition condition (A-B A-B) and the interference condi­ trieval of partial information with the likelihood ofa TOT tion (A-B A-D) both showed a high percentage ofTOTs (i.e., R. Brown & McNeill, 1966; Koriat & Lieblich, 1974; relative to the once-presented condition. Thus, they found Rubin, 1975; Vigliocco et aI., 1997; Vigliocco et al., that cue repetition led to more TOTs, regardless of the 1999). If partial related information is retrieved, it may level ofmemorability. be the presence of that information itself, regardless of whether or not the representation is activated, that in­ Accessibility Heuristic duces the TOT. Therefore, much ofthe data that support Koriat (1993, 1995) argued that feeling-of-knowing the direct-access view can also support the accessibility judgments are based on the amount and intensity ofpar­ view. Indeed, blocking effects on TOTs are also amen­ tial information that rememberers retrieve when they able to the accessibility view. However,only one published cannot recall a target answer. Koriat's view is inferential study directly supports the role ofthe retrieval ofrelated because the judgment is only made on accessible infor­ information in the formation ofTOTs (Schwartz & Smith, mation, and it is not based on inaccessible but available 1997). Therefore, the hypothesis should be considered targets. Schwartz and Smith (1997) hypothesized a sim­ tentative at best. Nonetheless, the research accumulating ilar basis for TOTs, arguing that the amount and intensity on inferential views of TOTs suggests that, in some cir­ of retrieved information may also playa role in the eti­ cumstances, TOTs are based on clues of memorability ology of TOTs. TOTs are caused by information that is rather than memorability itself. retrieved, but that information may be actually tangential to the sought-for target. The Heuristic Account ofAccuracy To test this hypothesis, Schwartz and Smith (1997) Inferential views, compared with direct-access theo­ presented participants with lists ofnonsense words. Each ries, require a more complicated explanation of why TOTs word was paired with the name ofa country, and some of are accurate predictors of performance. For inferential the words were also accompanied by line drawings of views, the actual presence ofthe target is not a given, and, fictional animals. Participants were told that each non­ therefore, accuracy must rely on the natural correlation sense word was the name of an animal, and the country between the factors that rememberers use to infer TOTs name was the habitat of that animal. For example, par­ and the factors that actually influence temporary forget­ ticipants might have seen Ye/key-Panama, which indi­ ting and subsequent retrieval. Accessibility theory, which cated that the "yelkey" is an animal that lives in Panama. centers on the evaluation ofpartial information, accounts Of the animals for which line drawings were provided, for accuracy by suggesting that people tend to retrieve halfwere also accompanied by information pertaining to more correct than incorrect information (Koriat, 1993). If the size and diet ofthe animal. The three encoding condi­ more correct than incorrect information is retrieved, TOTs tions were minimum-information (just the name-country will tend to be accurate in predicting eventual resolution pair), medium information (the name-country pair and or recall. The TOT experience may indicate-correctly line drawing), and maximum information (the name­ most ofthe time-that retrieval is indeed imminent. country pair, line drawing, and diet and habitat informa­ The TOT has been referred to as a cognitive heuristic tion). The conditions were designed to allow different (e.g., Schwartz, 1998; Smith, 1994). The heuristic ac­ amounts of information to be retrieved when the partie- count cogently explains why some TOTs are not resolved 390 SCHWARTZ or recognized. These TOTs may be spurious experiences tween object-level cognitions and meta-level cognitions caused by familiar cues or the retrieval ofrelated infor­ (see Figure 2). The object-level cognitions are typical cog­ mation. Indeed, in the case ofillusory TOTs, the person nitive processes, such as encoding, imaging, retrieving, cannot know the target answer (Schwartz, 1998). Thus, and so on. The meta-level cognitions, such as feelings of cases of"negative" TOTs (Vigliocco et aI., 1997), TOTs knowing or judgments oflearning, are cognitions specif­ for incorrect items (Rastle & Burke, 1996), and illusory ically directed toward object-level processes but are sep­ TOTs (Schwartz, 1998) may be best thought ofas errors arable from the cognitions. Nelson argued that monitor­ produced by inferential heuristics. Heuristics can there­ ing is the flow ofinformation from the object-level to the fore account for both the general accuracy ofTOTsand the meta-level and that control is the flow of information existence ofunresolved, unrecognized, or illusory TOTs. from the meta-level to the object-level. In this feedback The heuristic approach to TOTs is also consistent with system, the meta-level can access what the object level's Tulving's view on the doctrine ofconcordance. TOTs are actions are via monitoring and then change and adjust accurate at predicting memory performance because they them (control) (see Figure 2). arise from processes correlated with retrieval but not di­ TOTs play the role ofmonitoring by informing the re­ rectly from retrieval itself. This correlation does not memberers when an item may be retrievable. Function­ imply that the cognitive processes are identical, but only ally, TOTs may alert the rememberers that more time that they are linked. In fact, the linkage may occur only may be necessary to retrieve an item and not to terminate because of features of the external environment. Con­ the search (e.g., Ryan et aI., 1982). To the extent that one cordance does not preclude significant correlations be­ heeds the TOT and continues to attempt to retrieve an tween cognitive processes and phenomenology. Rather, item, one is controlling one's retrieval behavior. Thus, it suggests that the processes may be separable, as indeed TOTs provide the rememberers with useful information they appear to be with some TOTs. that they may then use to control mnemonic behavior. The critical assumption ofthe metacognitive model is TOTs AS METACOGNITION that monitoring and control are not perfect. Indeed, Nel­ son (1996) wrote that "the one new twist is to relax the The TOT phenomenon has been presented from three assumption, traditionally made by philosophers, that intro­ different perspectives: the psycholinguistic approach, spection is infallible" (p. 106). Nelson claims that mon­ which views TOTs as a "window" on word retrieval; the itoring is an "imperfect measuring devise of[one's] own memory perspective, which views TOTs as markers of cognitions" (p. 106). Nelson's claim is that metacogni­ available, but inaccessible, target memories; and the tion allows one to introspect on one's own cognition. Intro­ metacognitive perspective, which views TOTs as a phe­ spection, however,is not always valid (thus distinguishing nomenological experience about memory retrieval. Meta­ it from 19th century axioms concerning introspection). cognition, by definition, is concerned with cognitions One task ofthe researcher is to determine what kinds of about cognitions and thereby is necessarily related to the metacognition are accurate predictors ofperformance. study ofconsciousness (see Nelson, 1996). Because first­ For the most part, TOTs are valid indices oflater mem­ person TOTs are experiences whose referent is a cogni­ ory. Like other forms of metacognition, however, they tive process (retrieval), TOTs are indeed classifiable as are not always valid introspective tools. Illusory negative metacognitivejudgments. Nelson (1996) distinguishes be- TOTs and TOTs for incorrect items demonstrate the fal-

) META-LEVEL

Control MonItoring 'I Flow 01 Jint o r rn e tt o n

) OBJECT-LEVEL

Figure 2. Nelson and Narens's model. From "Why Investigate Metacognition?" by T. O. Nelson and L. Narens, 1994, in J. Metcalfe and A. P.Shimamura (Eds.), Metacognition: Knowing About Knowing (p, 11). Copyright 1994 by MIT Press. Reprinted with permission. TIP OF THE TONGUE 391

libilityof TOTs in measuring memory performance. More­ Metacognition: Knowing about knowing (pp. 185-205). Cambridge, over, resolution of objective TOTs is not perfect. As a MA: MIT Press. consequence, researchers must use care when using TOTs BJORK, R. A., & BJORK, E. L. (1992). A new theory ofdisuse and an old theory of stimulation fluctuation. In A. F. Healy, S. M. Kosslyn, & to study retrieval processes. Indeed, TOTs, like metacog­ R. M. Shiffrin (Eds.), From learning processes to cognitive pro­ nition in general, offer us a "lens" that brings phenome­ cesses: Essays in honor ofWilliam K. Estes (Vol. 2, pp. 35-67). Hills- nology into focus, as opposed to a "window" on the na­ dale, NJ: Erlbaum. I ture of retrieval. BROWN, A. S. (1991). A review of the tip-of-the-tongue experience. Psychological Bulletin, 109,204-223. BROWN, A. S., & NIX,L. A. (1996). Age-related changes in the tip-of­ CONCLUSIONS AND GOALS the-tongue experience. American Journal ofPsychology, 109, 79-91. FOR THE FUTURE BROWN, R., & McNEILL,D. (1966). The "tip ofthe tongue" phenomenon. Journal ofVerbal Learning & Behavior,S, 325-337. There are four important claims in this article. First, BRUCE, c., & HOWARD, D. (1988). Why don't Broca's aphasics cue themselves? An investigation ofphonemic cueing and tip ofthe tongue TOTs and word retrieval are experimentally dissociable information. Neuropsychologia, 26, 253-264. and may partially arise via different mechanisms. Thus, BURKE, D. M., MACKAY, D. G., WORTHLEY, J. S., & WADE, E. (1991). caution should be used when using TOTs to study the re­ On the tip ofthe tongue: What causes word finding failures in young trieval process. Second, the study ofTOTs provides im­ and older adults? Journal ofMemory & Language, 30, 542-579. CONNOR, L. T., BALaTA, D. A., & NEELY, J. H. (1992). On the relation portant empirical advantages for the investigation of between feeling of knowing and lexical decision: Persistent sub­ phenomenology in general because TOTs are easily in­ threshold activation or topic familiarity. Journal ofExperimental duced in the laboratory, and laboratory TOTs resemble Psychology: Learning. Memory, & Cognition, 18, 544-554. naturalistic ones. Furthermore, a sizable database con­ ELBERS, L. (1985). A tip-of-the-tongue experience at age two? Journal cerning TOTs already exists. TOTs appear to be a uni­ ofChild Language, 12,353-365. FINLEY, G. E., & SHARP, T. (1989). Name retrieval by the elderly in the versal phenomenological experience, since a common­ tip-of-the-tongue paradigm: Demonstrable success in overcoming language term exists for it in many languages. Third, initial failure. Educational Gerontology, 15,259-265. although many TOTs may arise from direct-access mech­ FUNNELL, M., METCALFE, 1., & TSAPKANI, K. (1996). In the mind but anisms, some TOTs also arise from inferential mecha­ not on the tongue: Feeling ofknowing in an anomie patient. In L. M. Reder (Ed.), Implicit memory and metacognition (pp, 171-194). nisms. Fourth, many aspects of research refute the doc­ Hillsdale, NJ: Erlbaum. trine of concordance. Perhapsthe most appropriate guiding GARDINER, J. M., & JAVA, R. I. (1993). Recognising and remembering. principle for TOT research is that of the metacognitive In A. F. Collins, S. E. Gathercole, M. A. Conway, & P. E. Morris approach-namely, that certain meta-level processes (Eds.), Theories ofmemory (pp. 163-188). Hillsdale, NJ: Erlbaum. exist to monitor and control object-level cognition and HARLEY, T. A., & BOWN, H. E. (1998). What causes a tip-of-the-tongue state? Evidence for lexical neighbourhood effects in speech produc­ behavior. tion. British Journal ofPsychology, 89, 151-174. What are the important directions for future research IWASAKI, N., VIGLIOCCO, G., & GARRETT, M. F. (in press). Adjectives to take? We still know very little concerning the scien­ and adjectival nouns in Japanese: Psychological processes in sentence tific bases ofconsciousness, nor do we know very much production. In Japanese/Korean Linguistics (Vol. 8). Stanford, CA: Stanford University Press. concerning TOTs. Future research in this area is open to JACOBY, L. L., KELLEY, C. M., & DYWAN, 1. (1989). Memory attribu­ many different directions and perspectives (see A. S. tions. In H. L. Roediger III & F.I. M. Craik (Eds.), Varieties ofmem­ Brown, 1991). In the current view, the most theoretically ory and consciousness: Essays in honour ofEndel Tulving (pp. 391­ rich area in TOT research is the nature and cause ofthe 422). Hillsdale, NJ: Erlbaum. phenomenological experience of the TOT. Current data JAMES, W. (1890). The principles ofpsychology: Vol. 1. New York: Holt. JONES, G. V. (1988). Analyzing memory blocks. In M. M. Gruneberg, suggest a complexity of the nature of the TOT experi­ P.E. Morris, & R. N. Sykes (Eds.), Practical aspects ofmemory: Cur­ ence and the interaction between phenomenology and rent research and issues (Vol. I, pp. 215-220). New York: Wiley. object-level cognition in general. Metacognition re­ JONES, G. V.(1989). Back to Woodworth: Role ofinterlopers in the tip­ search has shown that it can avoid the pitfalls of intro­ of-the-tongue phenomenon. Memory & Cognition, 17,69-76. JONES, G. v., & LANGFORD, S. (1987). Phonological blocking in the tip spectionism (Nelson, 1996) and that research into phe­ ofthe tongue state. Cognition, 26, 115-122. nomenological experience is again "fair game." KOHN, S. E., WINGFIELD, A., MENN,L., GOODGLASS, H., BERKO GLEA­ SON, J.. & HYDE, M. (1987). Lexical retrieval: The tip-of-the-tongue REFERENCES phenomenon. Applied Psycholinguistics, 8, 245-266. KORIAT, A. (1993). How do we know that we know? The accessibility ac­ ANDERSON, M. c., & NEELY, J. H. (1996). Interference and inhibition in count ofthe feeling ofknowing. Psychological Review, 100,609-639. memory retrieval. In E. L. Bjork & R. A. Bjork (Eds.), Memory KORIAT, A. (1995). Dissociating knowing and the feeling ofknowing: (pp. 237-417). San Diego: Academic Press. Further evidence for the accessibility model. Journal ofExperimen­ ASTELL, A. J., & HARLEY, T. A. (1996). Tip-of-the-tongue states and tal Psychology: General, 124, 311-333. lexical access in dementia. Brain & Language, 54, 196-215. KORIAT. A. (1997). Monitoring one's own knowledge during study: A BAK, B. (1987). The tip-of-the-tongue phenomenon: A Polish view. Pol­ cue-utilization approach to judgments oflearning. Journal ofExper­ ish Psychological Bulletin, 18,21-27. imental Psychology: General, 126, 349-370. BENJAMIN, A. S., BJORK, R. A., & SCHWARTZ, B. L. (1998). The mis­ KORIAT, A., & LIEBLICH, I. (1974). What does a person in a "TOT" state measure ofmemory: When retrieval fluency is misleading as a meta­ know that a person in a "don't know" state doesn't know. Memory & mnemonic index. Journal ofExperimental Psychology: General, Cognition, 2, 647-655. 127,55-68. KORIAT. A., & LIEBLICH. 1..(1977). A study of memory pointers. Acta BJORK, R. A. (1994). Memory and metamemory considerations in the Psychologica, 41, 151-164. training of human beings. In 1. Metcalfe & A. P. Shimamura (Eds.), KOZLOWSKI, L. T. (1977). Effects of distorted auditory and ofrhyming 392 SCHWARTZ

cues on retrieval of tip-of-the-tongue words by poets and nonpoets. ments oflearning and feelings ofknowing. Psychonomic Bulletin & Memory & Cognition.S, 477-481. Review, 1,357-375. MATISON, R., MAYEUX, R., ROSEN, J., & FAHN, S. (1982). "Tip-of-the­ SCHWARTZ, B. L. (1998). Illusory tip-of-the-tongue states. Memory, 6, tongue" phenomenon in Parkinson disease. Neurology, 32,567-570. 623-642. MAYLOR, E. A. (1990). Recognizing and naming faces: Aging, memory SCHWARTZ, B. L., & METCALFE, 1. (1992). Cue familiarity but not tar­ retrieval, and the tip ofthe tongue state. Journal ofGerontology, 45, get retrievability enhances feeling-of-knowing judgments. Journal of 215-226. Experimental Psychology: Learning, Memory. & Cognition, 18, METCALFE, J. (1993). Novelty monitoring, metacognition, and control 1074-1083. in a composite holographic associative recall model: Interpretations SCHWARTZ, B. L., & METCALFE, J. (1994). Methodological problems for Korsakoff amnesia. Psychological Review, 100, 3-22. and pitfalls in the study of human metacognition. In 1. Metcalfe & METCALFE, J., SCHWARTZ, B. L., & JOAQUIM, S. G. (1993). The cue fa­ A. P. Shimamura (Eds.), Metacognition: Knowing about knowing miliarity heuristic in metacognition. Journal ofExperimental Psy­ (pp. 93-114). Cambridge, MA: MIT Press. chology: Learning, Memory, & Cognition, 19, 851-861. SCHWARTZ, B. L., & SMITH, S. M. (1997). The retrieval of related in­ MEYER, A. S., & BOCK, K. (1992). The tip-of-the-tongue phenomenon: formation influences tip-of-the-tongue states. Journal ofMemory & Blocking or partial activation? Memory & Cognition, 20, 715-726. Language, 36, 68-86. MIOZZO, M., & CARAMAZZA, A. (1997). Retrieval of lexical-syntactic SCHWARTZ, B. L., TRAVIS, D. M., CASTRO, A. M., & SMITH, S. M. (in features in tip-of-the-tongue states. Journal ofExperimental Psy­ press). The phenomenology of real and illusory tip-of-the-tongue chology: Learning, Memory, & Cognition, 23, 1410-1423. states. Memory & Cognition. MURAKAMI, Y.(1980). On the memory unit within kana-letter and kanji­ SMITH, S. M. (1994). Frustrated feelings ofimminent recall: On the tip­ letter words in the tip ofthe tongue phenomenon. Japanese Journal of-the tongue. In 1.Metcalfe & A. P. Shimamura (Eds.), Metacognition: ofPsychology, 51, 41-44. Knowing about knowing (pp. 27-46). Cambridge, MA: MIT Press. NELSON, T.O. (1984). A comparison ofcurrent measures ofthe accuracy SMITH, S. M., BALFOUR, S. P., & BROWN, J. M. (1994). Effects of'prac­ offeeling-of-knowing predictions. Psychological Bulletin, 95, 109-133. tice on tip-of-the-tongue states. Memory, 2, 31-49. NELSON, T. O. (1996). Consciousness and metacognition. American TULVING, E. (1983). Elements ofepisodic memory. Oxford: Oxford Psychologist, 51,102-116. University Press. NELSON, T. 0., GERLER, D., & NARENS, L. (1984). Accuracy offeeling TuLVING, E. (1989). Memory: Performance, knowledge, and experience. ofknowing judgments for predicting perceptual identification and re­ European Journal ofCognitive Psychology, 1,3-26. learning.Journal ofExperimental Psychology: General, 113, 282-300. TuLVING, E., & PEARLSTONE, Z. (1966). Availability versus accessibility NELSON, T. 0., & NARENS, L. (1990). Metamemory: A theoretical of information in memory for words. Journal of Verbal Learning & framework and new findings. In G. H. Bower (Ed.), The psychology Verbal Behavior,S, 381-391. oflearning and motivation (Vol. 26, pp. 125-141). San Diego: Aca­ VIGLIOCCO, G., ANTONINI, T., & GARRETT, M. F. (1997). Grammatical demic Press. gender is on the tip of Italian tongues. Psychological Science, 8, NELSON, T. 0., & NARENS, L. (1994). Why investigate metacognition? 314-317. In 1. Metcalfe & A. P. Shimamura (Eds.), Metacognition: Knowing VIGLIOCCO, G., VINSON, D. P.,MARTIN, R. c, & GARRETT, M. F.(1999). about Knowing (pp. 1-25). Cambridge, MA: MIT Press Is "count" and "mass" information available when the noun is not? PERFECT, T. J., & HANLEY, J. R. (1992). The tip-of-the-tongue phe­ An investigation of tip of the tongue states in anomia. Journal of nomenon: Do experimenter-presented interlopers have any effect? Memory & Language, 40, 534-558. Cognition, 45, 55-75. WELLMAN, H. M. (1977). Tip ofthe tongue and feeling ofknowing ex­ RAJARAM, S. (1993). Remembering and knowing: Two means ofaccess periences: A developmental study ofmemory monitoring. Child De­ to the personal past. Memory & Cognition, 21, 89-102. velopment,48,13-21. RAJARAM, S., & ROEDIGER, H. L., III (1997). Remembering and know­ WIDNER, R. L., SMITH, S. M., & GRAZIANO, W. G. (1996). The etTects ing as states ofconsciousness during retrieval. In 1. D. Cohen & 1.W. ofdemand characteristics on the reporting oftip-of-the-tongue states Schooler (Eds.), Scientific approaches to consciousness (pp. 213­ and feeling-of-knowing states. American Journal ofPsychology, 109, 240). Hillsdale, NJ: Erlbaum. 525-538. RASTLE, K. G., & BURKE, D. M. (1996). Priming the tip ofthe tongue: YANIV, I., & MEYER, D. E. (1987). Activation and metacognition of in­ Effects ofprior processing on word retrieval in young and older adults. accessible stored information: Potential bases for incubation effects Journal ofMemory & Language, 35, 586-605. in problem solving. Journal ot' Experimental Psychology: Learning. READ, J. D., & BRUCE, D. (1982). Longitudinal tracking ofdifficult mem­ Memory. & Cognition, 13,187-205. ory retrievals. Cognitive Psychology, 14,280-300. REASON, J. T., & Lucus, D. (1984). Using cognitive diaries to investi­ NOTES gate naturally occurring memory blocks. In 1. Harris & P. E. Morris (Eds.), Everyday memory, actions. and absent mindedness (pp. 53­ I. Throughout this paper, the terms accessibility and availability are 70). London: Academic Press. defined in the sense intended by Tulving and Pearlstone (1966; also see REDER, L. M. (1987). Selection strategies in question answering. Cog­ Bjork & Bjork, 1992).Availability refers to the sum total ofinformation nitive Psychology, 19,90-138. in memory. Accessibility refers to that which is currently retrievable. REDER, L. M., & RITTER, F. E. (1992). What determines initial feeling 2. Full copies oftransliterations can be made available bye-mailing of knowing? Familiarity with question terms, not with the answer. the author. Journal ofExperimental Psychology: Learning. Memory, & Cogni­ 3. This hypothesis is potentially problematic based on the following tion, 18,435-451. logic. The conditions vary with respect to recall in the initial phase, thus ROEDIGER, H. L., III (1996). Memory illusions. Journal ofMemory & creating different pools of unrecalled targets on which TOTs may be Language, 35, 76-100. made. The condition with the highest initial recall (A-B A-B) creates RUBIN, D. C. (1975). Within word structure in the tip-of-the-tongue phe­ the smallest pool, presumably with the least variance and potentially the nomenon. Journal ofVerbalLearning & VerbalBehavior, 14,392-397. most difficult now. Nonetheless, empirically, Metcalfe et al. (1993) ob­ RYAN, M. P., PETTY, C. R., & WENZLAFF, R. M. (1982). Motivated re­ served significantly higher recognition (Experiments 1-3) and second­ membering efforts during tip-of-the-tongue states. Acta Psycholog­ chance recall (Experiment 4) in the A-B A-B condition. The hypothe­ ica, 51,137-147. sis is justified by this empirical finding. Furthermore, the A-B A-D SCHWARTZ, B. L. (1994). Sources ofinformation in metamemory: Judg- condition resulted in more TOTs than the A-B C-D condition. TIPOF THE TONGUE 393

APPENDIX A APPENDIXB Survey of Spoken Languages That Translations ofExpressions Use and Do Not Use the "Tongue" Metaphor Using the "Tongue" Metaphor Use "Tongue" Metaphor Do Not Use "Tongue" Metaphor "On the Tongue" Cheyenne Indo-European Languages Jaru Afrikaans Icelandic Marathi Armenian Norwegian Bulgarian Slovak Czech Swedish Danish Dutch "On Tip/Point/Head ofthe Tongue" English Afrikaans Farsi Arabic Flemish Armenian French Bulgarian German Chamarro Gujarati Czech Haitian Creole Danish Hindi Dutch Irish English Italian Estonian Marathi Farsi Norwegian Finnish Polish Flemish Portuguese French Russian German Serbo-Croatian Gujarati Slovak Haitian Creole Spanish Hebrew Swedish Hungarian Urdu Italian Welsh Polish Yiddish Portuguese Russian Non-Indo-European Languages Spanish Arabic American Sign Language Tamil Chamarro Amharic Turkish Cheyenne Indonesian Urdu Chinese (Cantonese) Kalenjin Vietnamese Chinese (Mandarin) Kiswahili Yiddish Estonian "On the Top ofthe Tongue" Finnish Irish Hausa Serbian Hebrew Hungarian "On the Front ofthe Tongue" Ibo Welsh Japanese "Sparkling at the End ofthe Tongue" Jaru Korean (1) Korean Tamil "In the Mouth and Throat" Turkish Cantonese Chinese Vietnamese Mandarin Chinese Hausa Hindi Ibo Japanese Korean (2)

(Manuscript received July 13, 1998; revision accepted for publication March 5,1999.)