CHAPTER 17 Consciousness in Hypnosis John F. Kihlstrom Abstract correlates of hypnotic suggestion revealed by brain imaging. In hypnosis, subjects respond to suggestions for imaginative experiences that can involve alterations in conscious perception, mem­ ory, and action. However, these phenom­ Consciousness in Hypnosis ena occur most profoundly in those subjects who are highly hypnotizable. The chap­ Hypnosis is a process in which one per­ ter reviews a number of these phenomena, son (commonly designated the subject) including posthypnotic amnesia; hypnotic responds to suggestions given by another analgesia; hypnotic deafness, blindness, and person (designated the hypnotist) for imag­ agnosia; and emotional numbing, with inative experiences involving alterations in an eye toward uncovering dissociations perception, memory, and the voluntary con­ between explicit and implicit memory, per­ trol of action. Hypnotized subjects can be ception, and emotion. These dissociative oblivious to pain; they hear voices that aren't phenomena of hypnosis bear a phenotypic there and fail to see objects that are clearly similarity to the "hysterical" symptoms char­ in their field of vision; they are unable to acteristic of the dissociative and conversion remember the things that happened to them disorders. The experience of involuntariness while they were hypnotized; and they carry in hypnotic response is considered in light of out suggestions after hypnosis has been ter­ the concept of automatic processing. Hyp­ minated, without being aware of what they nosis may be described as an altered state are doing or why. In the classic case, these of consciousness based on the convergence experiences are associated with a degree of of four variables: induction procedure, sub­ subjective conviction bordering on delusion jective experience, overt behavior, and psy­ and an experience of involuntariness border­ chophysiological indices - including neural ing on compulsion. 445 ~ I THE CAMBRIDGE HANDBOOK OF CONSCIOUSNESS The Importance of Individual tizable subjects are compared to those who Differences are insusceptible to hypnosis. In any case, measurement of hypnotizability is crucial to hypnosis research: There is no point in The phenomena of hypnosis can be quite studying hypnosis in individuals who cannot dramatic, but they do not occur in every­ experience it. one. Individual differences in hypnotizabil­ Some clinical practitioners believe that ity are measured by standardized psycho­ virtually everyone can be hypnotized, if logical tests, such as the Harvard Group only the hypnotist takes the right approach, Scale of Hypnotic Susceptibility, Form A but there is little evidence favoring this (HGSHS:A) or the Stanford Hypnotic Sus­ point of view. Similarly, some researchers ceptibility Scale, Form C (SHSS:C). These believe that hypnotizability can be enhanced psychometric instruments are essentially by developing positive attitudes, motiva­ work samples ofhypnotic performance, con­ tions, and expectancies concerning hypnosis sisting of a standardized induction of hypno­ (Gorassini & Spanos, 1987 ), but there is also sis accompanied by a set of 12 representative evidence that such interventions are heavily hypnotic suggestions. For example, on both laced with compliance (Bates & Kraft, 1991). HGSHS:A and SHSS:C, subjects are asked As with any other skilled performance, hyp­ to hold out their left arm and hand, and then notic response is probably a matter of both it is suggested that there is a heavy object in aptitude and attitude: Negative attitudes, the hand, growing heavier and heavier, and motivations, and expectancies can interfere pushing the hand and arm down. The sub­ with performance, but positive ones are not ject's response to each suggestion is scored by themselves sufficient to create hypnotic according to objective behavioral criteria virtuosity. (for example, if the hand and arm lower Hypnotizability is not substantially corre­ at least 6 inches over a specified interval lated with most other individual differences of time), yielding a single score represent­ in ability or personality, such as intelligence ing his or her hypnotizability, or responsive­ or adjustment (Hilgard, 196 5). However, in ness to hypnotic suggestions. Hypnotizabil­ the early 196os, Ronald Shor (Shor, Orne, ity, so measured, yields a quasi-normal distri­ & O'Connell, 1962), Arvid As (As, 1962), bution of scores in which most people are at and others found that hypnotizability was least moderately responsive to hypnotic sug­ correlated with subjects' tendency to have gestions, relatively few people are refractory hypnosis-like experiences outside of formal to hypnosis, and relatively few fall within hypnotic settings, and an extensive interview the highest level of responsiveness (Hilgard, study by Josephine Hilgard (1970) showed 1965). that hypnotizable subjects displayed a high Although most people can experience level of imaginative involvement in such hypnosis to at least some d~gree, the most domains as reading and drama. In 1974, Tel­ dramatic phenomena of hypnosis - the ones legen and Atkinson developed a scale of that really count as reflecting alterations in absorption to measure the disposition to have consciousness are generally observed in subjective experiences characterized by the those "hypnotic virtuosos" who comprise the full engagement of attention (narrowed or upper 10 to 15% of the distribution of hyp­ expanded), and blurred boundaries between notizability. Accordingly, a great deal of hyp­ self and object (Tellegen & Atkinson, 1974). nosis research involves a priori selection of Episodes of absorption and related phenom­ highly hypnotizable subjects, to the exclu­ ena such as "flow" (Csikszentmihalyi, 1990; sion of those of low and moderate hypno­ Csikszentmihalyi & Csikszentmihalyi, 1988) tizability. An alternative is a mixed design are properly regarded as altered states of in which subjects stratified for hypnotizabil­ consciousness in their own right, but they ity are all exposed to the same experimental are not the same as hypnosis and so are not manipulations, and the responses of hypno- considered further in this chapter. CONSCIOUSNESS IN HYPNOSIS 447 Conventional personality inventories, ations in consciousness. The sensory alter­ such as the Minnesota Multiphasic Person­ ations exemplified by hypnotic analgesia ality Inventory and California Psychological or deafness, as well as posthypnotic amne­ Inventory, do not contain items related to sia, are disruptions in conscious awareness: absorption, which may explain their failure The subject seems to be unaware of per­ to correlate with hypnotizability (Hilgard, cepts and memories that ought to be acces­ 1965). However, absorption is not wholly sible to phenomenal awareness. Similarly, unrelated to other individual differences in posthypnotic suggestion, as well as the expe­ personality. Recent multivariate research rience of involuntariness that frequently I has revealed five major dimensions - the accompanies suggested hypnotic experi­ "Big Five" - which provide a convenient ences, reflects a loss of control over cognition summary of personality structure: neuroti­ and behavior. cism (emotional stability), extraversion, Despite these considerations, the status of agreeableness, conscientiousness, and open­ hypnosis as an altered state of consciousness ness to experience (John, 1990; Wiggins & has been controversial (e.g., Gauld, 1992; Trapnell, 1997 ). Absorption and hypnotiz­ Hilgard, 1971; Kallio & Revensuo, 2003; ability are correlated with those aspects of Kirsch & Lynn, 1995; Shor, 1979a).' For openness that relate to richness of fantasy example, psychoanalytically inclined theo­ life, aesthetic sensitivity, and awareness of rists classified hypnosis as an instance of inner feelings, but not those that relate to adaptive regression, or regression in the intellectance or sociopolitical liberalism service of the ego (Fromm, 1979; Gill & (Glisky & Kihlstrom, 1993; Glisky, Tataryn, Brenman, 1959). Orne believed that the Tobias, & Kihlstrom, 1991). essence of hypnosis was to be found in Absorption is the most reliable corre­ "trance logic" (Orne, 1959), whereas Hil­ late of hypnotizability; by contrast, vivid­ gard argued that the phenomena of hyp­ ness of mental imagery is essentially uncor­ nosis were essentially dissociative in nature related with hypnosis (Glisky, Tataryn, & (Hilgard, 1973 b, 1977 ). By contrast, Sarbin Kihlstrom, 1995). However, the statistical and Coe described hypnosis as a form of relations between hypnotizability and either role-enactment (Sarbin & Coe, 1972 ); Bar­ absorption or openness are simply too weak ber asserted that the phenomena of hyp­ to permit confident prediction of an indi­ nosis could be produced by anyone who vidual's actual response to hypnotic sug­ held appropriate attitudes, motivations, and gestion (Roche & McConkey, 1990 ). So expectancies (Barber, 1969). far as the measurement of hypnotizabil­ More recently, both Woody and Bowers ity is concerned, there is no substitute for (Woody & Bowers, 1994; Woody & Sadler, performance-based measures such as the 1998) and Kihlstrom (Kihlstrom, 1984, Stanford and Harvard scales. 1992a, 1998) embraced some version of Hilgard's neodissociation theory of divided consciousness. By contrast, the "sociocogni­ The Controversy over State tive" approach offered by Spanos (1986a, 1991) emphasized the motivated subject's Consciousness has two principal aspects: attempt to display behavior regarded as