The 4 principal stages in a criminal proceeding are discussed with a view toward determining the role that hypnosis can and does play in the
American judicial system. In the preliminary investigative stage, hypnosis is primarily a technique for the discovery of evidence and its use is largely unfettered by court imposed restrictions. In the pre-trial stage, however, hypno-related testimony will be screened for abuses in obtaining it. At the trial stage, hypno-related testimony is generally admissible as a basis for expressing an opinion concerning mental condition, although no opinion may be expressed concerning the truthfulness of statements made under hypnosis. Where the testimony of a trial witness has been enhanced by the prior induction of hypnosis, the extent to which taint has occurred is usually a question for the jury to determine. In cases of flagrant suggestion during the induction process, however, such testimony will not be allowed in evidence. Learned societies in the field of hypnosi8s must bear the responsibility for educating the judiciary on the limits of hypnosis as an evidentiary technique.

Worthington, T. S. (1979). The use in court of hypnotically enhanced testimony. International Journal of Clinical and Experimental Hypnosis, 27 (4), 402-416.

The leading judicial decisions on the use of hypnosis on witnesses are presented. Emphasis is on the increasing use of hypnosis by the police or prosecution with witnesses in criminal cases. Hypnosis has proved to be a valuable tool to learn facts not otherwise available. There is, however, a potential for abuse when the information learned is used directly as evidence in court or when the subjective certainty of the witness is increased to the point where cross-examination becomes ineffective. Safeguards are needed to prevent abuse.

Schafer, D. W.; Rubio, R. (1978). Hypnosis to aid the recall of witnesses. International Journal of Clinical and Experimental Hypnosis, 26, 81-91.
14 cases are presented of interrogation under hypnosis of witnesses and victims of crimes. Videotaping is considered essential for use of the court, if necessary. Interrogation of indicted people should be done only as an exception, if at all. The ideal case for hypnosis interrogation is with a witness or a victim where information is obtained which leads to evidence which itself will stand up in court without the need of the hypnosis interrogation to be presented as such. Guidelines for such interrogation are presented.

Hodge, J. R. (1976). The contractual aspects of hypnosis. International Journal of Clinical and Experimental Hypnosis, 24, 391-399.
No generally accepted theory of the essence of hypnosis is currently available, nor are any specific responses uniquely associated with hypnosis. A necessary, though not sufficient, aspect of hypnosis involves the subject’s preconceived expectations and selective attention to a series of agreements (“contracts”) which are developed between patient and therapist before the induction, during the induction and deepening procedures, and during the operational phase. These contracts may be either implicit or explicit, but they can be identified in all hypnotic interactions. The skillful therapist will make the contracts explicit by defining, at least in general terms, what he expects. If the patient agrees, i.e., “sings the contract,” he is likely to comply with suggestions.

Sakata, Kenneth I. (1968). Report on a case of failure to dehypnotize and subsequent reputed aftereffects. International Journal of Clinical and Experimental Hypnosis, 16 (4), 221-228.
The failure of a hypnotized S to execute a suggested task may have contributed to a failure to dehypnotize, the repression of the unsuccessful task after awakening, and a prolongation or reinstatement of hypnosis 3 days later. Some interview material and procedures utilized in handling the problems encountered are presented. (French & German summaries) (PsycINFO Database Record (c) 2002 APA, all rights reserved)

Moss, C. Scott; Riggen, G.; Coyne, L.; Bishop, W. (1965). Some correlates of the use (or disuse) of hypnosis by experienced psychologist-therapist. International Journal of Clinical and Experimental Hypnosis, 13, 39-50.

147 psychologist-psychotherapists were compared on the basis of their attitude towards the employment of hypnosis as a technique in psychotherapy. 1 finding was the absence of extensive differences between the 2 groups in the use of most other therapy techniques, though the hypnosis-favorable group made somewhat more active use of a wider variety of approaches. Doctrine and experience level per se were not significant determinants of the behavior in question. A major finding was that those favorably disposed were inclined to represent themselves as significantly more objective (rather than clinical or intuitive) in their frame-of-reference. A number of significant biographical correlates were found which led to the advancement by speculation of vignettes of the 2 extreme attitude groups. (PsycINFO Database Record (c) 2002 APA, all rights reserved)

Orne, Martin T. (1965). Undesirable effects of hypnosis: The determinants and management. International Journal of Clinical and Experimental Hypnosis, 226-237.

Various kinds of complications arising from the use of hypnosis are reviewed. The distinction is drawn between the induction of hypnosis when it is perceived as an episodic event, as in a laboratory context, versus the effect when it is perceived as leading to permanent changes, as in a therapeutic context. An attempt is made to draw these and other distinctions in order to understand better the possible sources of difficulties. [Author Abstract]

Ludwig, Arnold M. (1964). An historical survey of the early roots of mesmerism. International Journal of Clinical and Experimental Hypnosis, 12 (4), 205-217.

Many believe that Franz Anton Mesmer helped lay the foundations upon which modern hypnotic theory and practice evolved. However, as one views the history of healing through suggestion prior to Mesmer, it becomes apparent that neither his theories nor his practices showed much originality. In fact, there is good evidence that Mesmer plagiarized the work of others. With this in mind, it appears that Mesmer”s contribution to later psychological healing and theory was related more to his personality than to his originality. (Journal Abstract)

Levitt, Eugene E.; Hershman, Seymour (1963). The clinical practice of hypnosis in the United States: A preliminary survey. International Journal of Clinical and Experimental Hypnosis, 11 (1), 55-65.

A preliminary survey of 301 clinical practitioners of hypnosis who responded to a questionnaire suggests that reported success in inducing hypnosis is unrelated to claimed experience with hypnosis. Children and adolescents are reported to be more susceptible than adults, but there is no sex difference reported. Type of training is generally unrelated to reported success as a hypnotist. Reported percentages of patients who attain various levels of hypnotic depth are generally in keeping with earlier reports. Unexpected reactions to being hypnotized were reported by one out of four respondents.

Pulver, Sydney E. (1963). Delusions following hypnosis. International Journal of Clinical and Experimental Hypnosis, 11, 11-22.

Delusions occurring after hypnosis in the nonpsychotic patient are usually a result of the interplay of 3 factors. (a) the development of rapid, tense, transference reactions in hypnosis; (b) the presence of major defects in the patient”s character structure; and (c) the occurrence of countertransference reactions on the part of the hypnotist which touch on a specific area of conflict within the patient. The presence of a chaperon or the use of tape recorders are not satisfactory preventive measures. Rather, the physician using hypnosis should focus upon: (a) preliminary psychological evaluation and selection of patients free from disposition to delusion formation, (b) identification of transference reactions and a willingness to discuss with patients, (c) awareness of his own emotional responses to the patient. Basic courses in psychiatry are recommended. (PsycINFO Database Record (c) 2002 APA, all rights reserved)

Moss, C. Scott; Logan, J. C.; Lynch, D. (1962). Present status of psychological research and training in hypnosis: A developing professional problem. American Psychologist, 17, 542-549. (Abstracted in American Journal of Clinical Hypnosis, 1963, 6, 82)

Anonymous questionnaires on training and research in hypnosis were returned by 54 of 55 psychology department chairmen with approved clinical psychology training programs and 39 of 85 American Medical Association approved medical schools. 8 psychology departments and 2 medical schools have courses in hypnosis. Unless the “psychological profession is more active in protecting its rights to research and clinical use of a methodology which is basically psychological, it may find itself legally excluded from the field.” (PsycINFO Database Record (c) 2002 APA, all rights reserved)

Marcus, Howard W.; Bowers, Margaretta K. (1961). Hypnosis and schizophrenia in the dental situation. A case report. International Journal of Clinical and Experimental Hypnosis, 9, 47-57. (In Index Medicus 61: 1228)

Author”s Summary
A case is presented of a schizophrenic patient, paranoid type, whose phobic fear of dentistry had resulted in the development of a delusional system: he would get well if his teeth were repaired under hypnosis. In reality, his need of dental care was severe. He had lost three teeth by extraction because of painful cavities which he could not permit to be treated with conventional methods. He presented deep cavities in his front teeth. The patient was consistently unable to make rapport with several psychiatrists and dental treatment was finally discontinued because of unwillingness to proceed without psychiatric supervision. Alternative methods of handling the situation and its implications are discussed.

McCartney, James L. (1961). A half century of personal experience with hypnosis. International Journal of Clinical and Experimental Hypnosis, 9, 23-33.

(Author”s Summary and Conclusions). “After fifty years of experience with hypnosis, it is evident that it is not a superficial and careless technic but should be utilized only by capable, trained physicians, as are the other complex and difficult medical technics. … In order to induce hypnosis, the patient must be perfectly willing to be hypnotized, he must have confidence in the practitioner, and he must concentrate on doing exactly as he is told. In selected cases, drugs or electrical impulses may be used for the initial induction of hypnotic sleep, but if hypnotherapy is to be continued, the physician must keep in contact with the patient by repeated suggestions. The technic used should fit the individual patient, but in most cases, verbal suggestions are all that is necessary to bring about dissociation. Hypnosis may be used to facilitate the beginning of mental catharsis, the establishment of transference, and may be easily instituted following narcosynthesis, electroshock therapy, minimum stimulus, or Sedac. Suggested activity under hypnosis may be carried out at a designated time, place, and manner after awakening. This is a result of autosuggestion and may be mistaken for psychopathic behavior. Such suggestions may be instituted by television, movies, radio, telephone, or recorded or written instruction. Hypnosis may be used to plant suggestions; if misused, it may create an obsessive-compulsive neurosis, while when properly used, it may overcome many functional symptoms and may be used to supplement other forms of psychotherapy” (p. 32).

Shaw, S. Irwin (1961). The dangers of hypnosis (the mental hypodermic) as applied to dentistry. International Journal of Clinical and Experimental Hypnosis, 9 (2), 53-58.

The author expresses the opinion that there are no inherent dangers in using hypnosis in dentistry, if the dentist is well-trained (including training in the psychodynamic factors involved, counter-transference, etc.) He indicates that dentists should not use hypnodontia with patients who are in psychiatric treatment, or recently had such treatment, without consulting with the physician or psychologist involved in the mental health treatment. “The qualified practitioner of hypnosis is always alert to possible involvements on the part of the patient, and perhaps including himself, in the emotional relationship connected with trance induction. It is this knowledge and full awareness of _possible_ dangers, which prevents harm to the dental patient, in the same way that the conscientious user of a hypodermic syringe, knowing of dangers involved, is always careful to avoid risks when making injections of drugs or chemicals into the patient” (p. 56).

Abramson, M. (1960). Danger! hypnotherapist at work. Bulletin, Hennepin County Medical Society, 31, 101-106.

The author reviews briefly pros and cons regarding the medical use of hypnosis. He concludes: “It is the author’s opinion, based on an extensive personal experience of over 15 years, that the use of hypnotherapy by a physician or dentist who has been properly trained and who uses this technique strictly within his field of competence carries with it no more (and probably less) ‘danger’ than the use of many other techniques of treatment used in medicine today.” [Abstract from American Journal of Clinical Hypnosis, 1960, 3, 120.}

Raginsky, Bernard B. (1959). Temporary cardiac arrest induced under hypnosis. International Journal of Clinical and Experimental Hypnosis, 7 (2), 53-68.
“An experiment is described in which the symptoms of syncope and temporary complete cardiac arrest were induced under hypnosis in a patient who had been operated on for a so-called Adams-Stokes syndrome and who had, until the time of the experiment, remained free of such symptoms. An attempt is made to correlate contemporary knowledge in explaining this phenomenon.
“It is pointed out that maturity in the biological sciences takes about twice as long to achieve as does maturity in the physical sciences. This holds especially true in the use of hypnosis” (p. 66).
The authors report that in attempting to reinduce a fainting episode, “We were not at all prepared for the complete cardiac arrest which followed the hallucinated episodes” (p. 59).

Marcuse, F. L.; Phipps, G. T. (1956). A demonstration of dental extraction with hypnotic anesthesia. Journal of Clinical and Experimental Hypnosis, 4, 2-4.

The authors report on a demonstration of dental extractions with two patients (of five patients with whom hypnosis was attempted). They describe successful results despite 3-minute inductions in people not pre-trained, a terse and abrupt approach by the dentist (who uses only hypnosis and refers non-responding patients elsewhere). “While the hypnotist demonstrated effectively what could be done with hypnosis, his theoretical orientaton as to why this had occurred can only be described as unfortunate. In response to questioning he stated and quite flatly: that in hypnosis there are no dangers (1); that hypnosis is essentially cardiovascular in nature; that drugs had no place along with hypnosis–despite the advice of Moss (2) that dentists should use hypnosis along with drugs routinely unless the latter is contraindicated. He expressed his attitude toward the use of local anesthetics by indicating that the package he had had was thrown away because it had become spoiled from disuse. Hypnosis was presented in effect as an all or nothing technique” (p. 3).

Meares, Ainslie (1954). History-taking and physical examination in relation to subsequent hypnosis. Journal of Clinical and Experimental Hypnosis, 2 (4), 291-295.

“Summary. The history-taking and physical examination of the initial interview can be so structured as to facilitate the subsequent induction of hypnosis. Rapport is established, and negative transference feelings are not allowed to develop. There must be no holding back or hiding of the real complaint with screen symptoms. Physical examination is a symbolic surrender and paves the way for the real surrender of passive hypnosis. If induction by an active method is anticipated, authoritative attitudes are introduced into the history-taking and physical examination” (p. 295).


Jensen, Stacia M.; Barabasz, Arreed; Barabasz, Marianne; Warner, Dennis (2001). EEG P300 event-related markers of hypnosis. American Journal of Clinical Hypnosis, 44 (2), 127-139.

Demonstrated that when subjects are stringently selected for hypnotizability and responses are time-locked to events, robust markers of hypnotic response emerge that reflect alterations in consciousness corresponding to subjects”subjective experiences of perceptual alteration. To further test this hypothesis, the researchers obtained EEG visual P300 event-related potentials (ERPs) from 20 high- and low-hypnotizable subjects (7 males and 13 females, aged 19-52 years). The effects of positive obstructive and negative obliterating instructions were tested during waking and alert hypnotic conditions. High-hypnotizables showed greater ERP amplitudes in response to the negative hallucination condition and lower ERP amplitudes in response to the positive obstructive hallucination when compared to the low-hypnotizables. Contrary to socio-psychological or role play conceptualizations, the hypnotic induction resulted in specific psychophysiological responses which could not be produced by waking imagination or by the lows who were trying to mimic hypnotic responding. (PsycINFO Database Record (c) 2002 APA, all rights reserved)

Barabasz, A.; Barabasz, M.; Jensen, S.; Calvin, S.; Trevisian, M.; Warner, D. (1999). Cortical event-related potentials show the structure of hypnotic suggestions is crucial. International Journal of Clinical and Experimental Hypnosis, 47 (1), 5-22.

Electroencephalographic cortical event-related potentials (ERPs) are affected by information processing strategies and are particularly appropriate for the examination of hypnotic alterations in perception. The effects of positive obstructive and negative obliterating instructions on visual and auditory P300 ERPs were tested. Twenty participants, stringently selected for hypnotizability, were requested to perform identical tasks during waking and alert hypnotic conditions. High hypnotizables showed greater ERP amplitudes while experiencing negative hallucinations and lower ERP amplitudes while experiencing positive obstructive hallucinations, in contrast to low hypnotizables and their own waking imagination-only conditions. The data show that when participants are carefully selected for hypnotizability and responses are time locked to events, rather robust physiological markers of hypnosis emerge. These reflect alterations in consciousness that correspond to participants’ subjective experiences of perceptual alteration. Accounting for suggestion type reveals remarkable consistency of findings among dozens of researchers.

In their Discussion the authors note that not all of the highly hypnotizable subjects demonstrated the changes predicted, consistent with Hilgard’s (1992)observation that individual differences in response remain even among high hypnotizables. Post-experimental inquiry revealed the sources of (non-predicted) response for these two people. “One, showing only a moderate ERP amplitude attenuation in the obstructive condition, noted she pictured a cardboard box in front of the computer monitor, but ‘I pictured a rather small box that didn’t block the entire screen!’ Another showed an apparently contradictory response, a markedly diminished amplitude in the negative hallucination that called for deafness during the auditory stimuli. This participant reported the perception of complete obliteration of all sounds and, therefore, showed no surprise ERP effect. ‘It was kind of scary when he (AB) said ‘deaf’ the second time. I couldn’t hear anything at all. I was glad when he touched my shoulder and it was OK to hear again. I don’t think I would do that again … I mean do the hypnotic suggestion as much!'” (pp. 17-18).

De Pascalis, Vilfredo (1999). Psychophysiological correlates of hypnosis and hypnotic susceptibility. International Journal of Clinical and Experimental Hypnosis, 47 (2), 117-143.

This article reviews and summarizes electroencephalographic (EEG)-based research on physiological and cognitive indicators of hypnotic responding and hypnotic susceptibility, with special attention to the author”s programmatic research in this area. Evidence that differences in attention levels may account for hypnotic depth and individual differences in hypnotizability is provided with traditional EEG rhythms, event-related potentials, and 40-Hz EEG activity. The alteration of stimulus perception may be a secondary effect with respect to allocation of attentional resources. In both nonhypnosis and hypnosis conditions, high hypnotizables appeared to show greater task-related EEG hemispheric shifts than did low hypnotizables. Findings concerning cognitive and physiological correlates of hypnotic analgesia are discussed with respect to hemispheric functioning in the apparent control of focused and sustained attention. The conclusion is that although a definitive EEG-based signature for hypnosis and hypnotizability is not yet established, there are a number of promising leads.

The authors conclude that their results support Hilgard””””s (1986) hypothesis that high hypnotizables are better able to focus attention on task-relevant stimuli than low hypnotizables; “show a greater 40-Hz EEG hemispheric specificity in both nonhypnotic and hypnotic conditions” (p. 134) which suggests “greater physiological flexibility (i.e., the subjective capacity to shift from one ””””state”””” to another)” (p. 134); exhibit more EEG beta activity during early stages of hypnotic inductions (especially Left hemisphere) though there is hemisphere balancing later — supporting Gruzelier””””s (1988, 1996) theory; show changes in ERP that can””””t be explained by a theory of goal directed strategies but are consistent with findings by Barabasz et al (1996) “showing that hypnotic alteration of stimulus perception operates early at the level of the detection of the signal as well as later at the level of response bias” (p. 134); and, given hypnotic analgesia suggestions, they “showed significantly smaller total, delta, and beta 1 amplitudes in the right hemisphere across all frontal, central, and posterior recordings so that a significantly more pronounced hemispheric asymmetry in favor of the left hemisphere was displayed” (p. 135).

De Pascalis, V.; Magurano, M. D.; Bellusci, A. (1999). Pain perception, somatosensory event-related potentials and skin conductance responses to painful stimuli in high, mid, and low hypnotizable subjects: Effects of differential pain reduction strategies. Pain, 83 (3), 499-508.
In this study, pain perception, somatosensory event-related potential (SERP) and skin conductance response (SCR) changes during hypnotic suggestions of Deep Relaxation, Dissociated Imagery, Focused Analgesia, and Placebo, compared with a Waking baseline condition, were investigated. SERPs were recorded from frontal, temporal, central, and parietal scalp sites. Ten high, 9 mid, and 10 low hypnotizable right-handed women participated in the experiment. The following measures were obtained: (1) pain and distress tolerance ratings; (2) sensory and pain thresholds to biphasic electrical stimulation delivered to the right wrist; (3) reaction time and number of omitted responses; (4) N2 (280+/-11 ms) and P3 (405+/-19 ms) peak amplitudes of SERPs to target stimuli delivered using an odd-ball paradigm; (5) number of evoked SCRs and SCR amplitudes as a function of stimulus repetition. Results showed, high, mid and low hypnotizables exhibited significant reductions of reported pain and distress ratings during conditions of Deep Relaxation/Suggestion of Analgesia, Dissociated Imagery and Focused Analgesia. High hypnotizable subjects displayed significant reductions in pain and distress levels compared to mid and low hypnotizables during Dissociated Imagery, Focused Analgesia and, to a lesser degree, during Deep Relaxation. Placebo condition did not display significant differences among hypnotizability groups. High hypnotizables, compared to mid and low hypnotizables, also showed significant increases in sensory and pain thresholds during Dissociated Imagery and Focused Analgesia. High, mid, and low groups showed significant reductions in P3 peak amplitudes across all hypnosis conditions and, to a lesser degree, during Placebo. The temporal cortical region was the most sensitive in differentiating SERP responses among hypnotizability groups. On this recording area the subjects highly susceptible to hypnosis displayed significantly smaller P3 and greater N2 peaks during Focused Analgesia than did the other hypnotizable groups. In this condition highly susceptible subjects also reported the highest number of omitted responses and the shortest Reaction Times. These subjects also showed faster habituation of SCRs when compared with mid and low hypnotizables. During Dissociated Imagery and Focused Analgesia, highly hypnotizable subjects also disclosed a smaller total number of evoked SCRs than did mid and low hypnotizable subjects. The results are discussed considering possible common and different mechanisms to account for the effects of different hypnotic suggestions.
Abstract from National Library of Medicine, PubMed

Kallio, Sakari; Revonsuo, Antti; Lauerma, Hannu; Hdmdldinen, Heikki; Lang, Heikki (1999). The MMN amplitude increases in hypnosis – a case study. Neuroreport, 10 (17), 3579-3582.
The neural mechanisms associated with hypnosis were investigated in a single highly hypnotizable subject by measuring the mismatch negativity (MMN) component of auditory ERP, reflecting the preattentive discrimination of change in stimulus flow, in normal baseline state and under hypnosis. It has been proposed that the frontal inhibition associated with hypnosis can be measured as a decrease in MMN. ERPs were elicited using the passive oddball paradigm with standard and deviant sine tone stimuli of 500 and 553 Hz respectively. The measurement was repeated in five separate sessions. In hypnosis the MMN was significantly larger compared to baseline. The results indicate that hypnosis can give rise to altered information processing in the brain even at a relatively early, i.e. preattentive level and that the larger MMN measured under hypnosis does not support frontal inhibition theory.

Crawford, Helen J.; Knebel, Timothy; Kaplan, Lyla; Vendemia, Jennifer M. C.; Xie, Min; Jamison, Scott; Pribram, Karl H. (1998). Hypnotic analgesia: 1. Somatosensory event-related potential changes to noxious stimuli and 2. Transfer learning to reduce chronic low back pain. International Journal of Clinical and Experimental Hypnosis, 46 (1), 92-132.

Fifteen adults with chronic low back pain (M = 4 years), age 18 to 43 years (M = 29 years), participated. All but one were moderately to highly hypnotizable (M = 7.87; modified 11-point Stanford Hypnotic Susceptibility Scale, Form C [Weitzenhoffer & Hilgard, 1962]), and significantly reduced pain perception following hypnotic analgesia instructions during cold-pressor pain training. In Part 1, somatosensory event-related potential correlates of noxious electrical stimulation were evaluated during attend and hypnotic analgesia (HA) conditions at anterior frontal (Fp1, Fp2), midfrontal (Fe, F4), central (C3, C4), and parietal (P3, P4) regions. During HA, hypothesized inhibitory processing was evidenced by enhanced N140 in the anterior frontal region and by a prestimulus positive-ongoing contingent cortical potential at Fp1 only. During HA, decreased spatiotemporal perception was evidenced by reduced amplitudes of P200 (bilateral midfrontal and central, and left parietal) and P300 (right midfrontal and central). HA led to highly significant mean reductions in perceived sensory pain and distress. HA is an active process that requires inhibitory effort, dissociated from conscious awareness, where the anterior frontal cortex participates in a topographically specific inhibitory feedback circuit that cooperates in the allocation of thalamocortical activities. In Part 2, the authors document the development of self-efficacy through the successful transfer by participants of newly learned skills of experimental pain reduction to reduction of their own chronic pain. Over three experimental sessions, participants reported chronic pain reduction, increased psychological well-being, and increased sleep quality. The development of “neurosignatures of pain” can influence subsequent pain experiences (Coderre, Katz, Vaccarino, & Malzack, 1993; Melzack, 1993) and may be expanded in size and easily reactivated (Flor & Birbaumer, 1994; Melzack, 1991, 1993). Therefore, hypnosis and other psychological interventions need to be introduced early as adjuncts in medical treatments for onset pain before the development of chronic pain.

The authors suggest that “the anterior frontal region deals with the active allocation of attention and disattention, whereas spatiotemporal aspects of the somatosensory perceptions involve the posterior cortical systems” (p. 113) They acknowledge that “other inhibitory pain systems are actively interacting with the frontal attentional system, including the limbic and thalamic systems” and mention evidence that the inhibitory processing “may extend as far as spinal cord antinociceptive mechanisms as evidenced by reductions in brief latency (Hagbarth & Finer, 1963) and R-III amplitude (Kiernan, Dane, Phillips, & Price, 1995) of spinal reflexes” (p. 113). Both pain perception and strategies of pain control may involve the anterior cingulate cortex (Kropotov et al. 1997), which has many connections with anterior frontal cortex “and is thought to be an area that organizes responses to noxious stimuli” (p. 113).
For the chronic low back pain Ss there were reductions in reported low back pain during the experimental sessions, and significant improvements in psychological well-being and sleep quality across the three sessions. “The importance of developing self-efficacy through learning to control experimental pain and the understanding of one’s own attentional and disattentional abilities was demonstrated as being a significant intervention in the modulation and control of chronic pain” (p. 123).

Danziger, N.; Fournier, E.; Bouhassira, D.; Michaud, D.; De Broucker, T.; Santarcangelo, E.; Carli, G.; Chertock, L.; Willer, J. C. (1998). Different strategies of modulation can be operative during hypnotic analgesia: A neurophysiological study. Pain, 75 (1), 85-92. Keywords: analgesia/anesthesia, autonomic nervous system, EEG, electrical stimulation, event related potential (ERP), inhibition, neurophysiology, pain, pain threshold, reflex, suggestion

Nociceptive electrical stimuli were applied to the sural nerve during hypnotically-suggested analgesia in the left lower limb of 18 highly susceptible subjects. During this procedure, the verbally reported pain threshold, the nociceptive flexion (RIII) reflex and late somatosensory evoked potentials were investigated in parallel with autonomic responses and the spontaneous electroencephalogram (EEG). The hypnotic suggestion of analgesia induced a significant increase in pain threshold in all the selected subjects. All the subjects showed large changes (i.e., by 20% or more) in the amplitudes of their RIII reflexes during hypnotic analgesia by comparison with control conditions. Although the extent of the increase in pain threshold was similar in all the subjects, two distinct patterns of modulation of the RIII reflex were observed during the hypnotic analgesia: in 11 subjects (subgroup 1), a strong inhibition of the reflex was observed whereas in the other seven subjects (subgroup 2) there was a strong facilitation of the reflex. All the subjects in both subgroups displayed similar decreases in the amplitude of late somatosensory evoked cerebral potentials during the hypnotic analgesia. No modification in the autonomic parameters or the EEG was observed. These data suggest that different strategies of modulation can be operative during effective hypnotic analgesia and that these are subject-dependent. Although all subjects may shift their attention away from the painful stimulus (which could explain the decrease of the late somatosensory evoked potentials), some of them inhibit their motor reaction to the stimulus at the spinal level, while in others, in contrast, this reaction is facilitated.
Abstract from National Library of Medicine, PubMed

Barabasz, Arreed; Barabasz, Marianne (1997, August). Altered brain activity shows the structure of hypnotic suggestions is crucial. [Paper] Presented at the annual meeting of the American Psychological Association, Chicago, IL. (Abstract was published in Psychological Hypnosis, Winter-Spring 1998, Vol 7, No. 1, pp. 3-4.)

Recently, Kirsch and Lynn (1995) helped to converge understandings of hypnosis and at the same time stimulated renewed consideration of the central issues. Kihlstrom (1996, p.1) reminded us that trance versus non-trance as well as persistent individual differences versus experimental manipulation “continue to divide the field.” Hilgard (1992, p. 80) emphasized that the “basic reason” hypnosis theories are in disarray stems from the lack of “any truly distinguishing basis – psychological, physiological or neurophysiological – by which to distinguish sharply between the established hypnotic condition (call it ‘trance’ or any other name) and normal waking consciousness.” Cortical event related postentials (ERPs) provide one way of shedding light on this issue.
This study tested the effects of positive obstructive and obliterating instructions on visual and auditory EEG P300 ERPs. Considering issues raised by Spiegel and Barabasz (1988), 20 participants, stringently selected for hypnotizability, were requested to perform identical tasks during waking and alert hypnotic conditions. High hypnotizables showed greater ERP amplitudes while experiencing negative hallucinations (i.e., a suggestion not to perceive stimuli) and lower ERP amplitudes while experiencing positive obstructive hallucinations (i.e., a suggestion to perceive competing stimuli instead of the presented ones) in contrast to low hypnotizables and their own waking imagination only conditions. Accounting for suggestion type reveals remarkable consistency of findings among dozens of researchers.
The findings do not contradict the real and impressive effects of hypnosis that result from immediate social influences, social context and personal abilities (Kirsch, Council, Mobayed, 1987; Lynn, Rhue & Weekes, 1990). Given the leptokurtic distribution of hypnotizability in the general population, social influence may entirely account for many of the hypnotic phenomena seen in research and clinical situations, which tap primarily those of moderate hypnotizability. However, the present study does show that when participants are very stringently selected and responses are time locked to events, robust physiological markers of hypnosis emerge that reflect alterations in consciousness and correspond to subjective experiences of perceptual alteration.

Jasiukaitis, Paul; Nouriani, Bita; Hugdahl, Kenneth; Spiegel, David (1997). Relateralizing hypnosis: Or, have we been barking up the wrong hemisphere?. International Journal of Clinical and Experimental Hypnosis, 45 (2), 158-177.

Research and theory over the past couple decades have suggested that the right cerebral hemisphere might be the focus of brain activity during hypnosis. Recent evidence from electrodermal responding, visual event-related potentials, and Stroop interference, however, can make a case for a role of the left hemisphere in some hypnotic phenomena. Although hemispheric activation on hypnotic challenge may depend in large part on the kind of task the challenge might involve, several general aspects of hypnosis might be more appropriately seen as left-rather than right-hemisphere brain functions. Among these are concentrated attentional focus and the role of language in the establishment of hypnotic reality. A left-hemisphere theory of hypnosis is discussed in light of recent findings and theories about a left-hemisphere basis for synthetic or generational capabilities (Corballis, 1991) and a neuro-evolutionary model of a left-hemisphere dopaminergic activation system for the implementation of predetermined motor programs (Tucker & Williamson, 1984). — Journal Abstract

Barabasz, Arreed F.; Barabasz, Marianne; Jensen, Stacia (1995, November). Effects of hypnosis on cortical event-related potentials during visual and olfactory hypnotic hallucinations. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, San Antonio, TX.

Slotnick and London showed that different wording of suggestions led to very different results, which explains why our study on negative hallucinations and Spiegel’s study had opposite results.
This study is still ongoing. Screened for highs who passed visual and olfactory hallucinations and lows who passed only motoric items on hypnotizability tests. Trained Ss with eyes open induction, and lows had instructions to simulate hypnosis. (Used the eyeroll induction, eyes open.)
Did waking administration of alternating checkerboard pattern on computer screen. Then did eyes open hypnotic induction plus a depth check to make sure they were deep (assign number; then instructed raise a finger when you double it; then again, raise a finger when you double it). Then used checkerboard design again.
Obstructive visual hallucination – “imagine traveling through space, a dark nebula” (better than imagining you are blind. Lows had no difference in waking, obstructive hallucination, and negative hallucination. The highs did–looks like they had to see it before they couldn’t see it. “The dark nebula envelopes you completely, and now you can see nothing.”

Schnyer, David M.; Allen, John J. (1995). Attention-related electroencephalographic and event-related potential predictors of responsiveness to suggested posthypnotic amnesia. International Journal of Clinical and Experimental Hypnosis, 43 (3), 295-315.

Higher frequency electroencephalographic (EEG) activity around 40 Hz has been shown to play a role in cognitive functions such as attention. Furthermore, event-related brain potential (ERP) components such as N1 and P1 are sensitive to selective attention. In the present study, 40-Hz EEG measures and early ERP components were employed to relate selective attention to hypnotic response. Participants were 20 low hypnotizable individuals, half assigned as simulators, and 21 high hypnotizable individuals. Each of these groups was subsequently divided into two groups based on recognition amnesia scores. The four groups differed in 40-Hz (36-44 Hz) EEG spectral amplitude recorded during preinduction resting conditions but not in EEG amplitude postinduction. The groups also differed in N1 amplitudes recorded during hypnosis. Regression analysis revealed that these effects only distinguish the high hypnotizable participants who experienced recognition amnesia from all other groups. The findings support the role of selective attention in hypnotic responsiveness, and the utility of subdividing high hypnotizable individuals is discussed.

Crawford, Helen J. (1994). Brain dynamics and hypnosis: Attentional and disattentional processes. International Journal of Clinical and Experimental Hypnosis, 42 (3), 204-232.

This article reviews recent research findings, expanding an evolving neuropsychophysiological model of hypnosis (Crawford, 1989; Crawford & Gruzelier, 1992), that support the view that highly hypnotizable persons (highs) possess stronger attentional filtering abilities than do low hypnotizable persons, and that these differences are reflected in underlying brain dynamics. Behavioral, cognitive, and neurophysiological evidence is reviewed that suggests that highs can both better focus and sustain their attention as well as better ignore irrelevant stimuli in the environment. It is proposed that hypnosis is a state of enhanced attention that activates an interplay between cortical and subcortical brain dynamics during hypnotic phenomena, such as hypnotic analgesia. A body of research is reviewed that suggests that both attentional and disattentional processes, among others, are important in the experiencing of hypnosis and hypnotic phenomena. Findings from studies of electrocortical activity, event-related potentials, and regional cerebral blood flow during waking and hypnosis are presented to suggest that these attentional differences are reflected in underlying neurophysiological differences in the far fronto-limbic attentional system.

Crawford, Helen J. (1994). Brain systems involved in attention and disattention (hypnotic analgesia) to pain. In Pribram, Karl H. (Ed.), Origins: Brain and self organization (pp. 661-679). Hillsdale, NJ: Lawrence Erlbaum Associates.

Data are reviewed from regional cerebral blood flow, EEG, and somatosensory event-related potential (SERP; both scalp and intracranial) studies of attention to and disattention (hypnotic analgesia) of painful stimuli to provide further evidence for two neurophysiological systems of pain involving the cortex: (1) the epicritic, sensory system of pain associated with the parietal, posterior region, and (2) the protocritic, distress, comfort-discomfort system of pain associated with the far fronto- limbic region. Studies of neurophysiological changes accompanying suggested hypnotic analgesia support the hypothesis that the executive controller of the far frontal cortex, via the far fronto-limbic attentional system, acts as a gate against the ascent of painful stimuli into conscious awareness by ‘directing’ downward the inhibition of incoming somatosensory information coming from the thalamic region. In hypnotically responsive individuals who could eliminate the perception of pain, reviewed studies demonstrated increased regional cerebral blood in the frontal and somatosensory regions, shifts in hemispheric dominance of EEG theta power, differential surface SERP topographical patterns in the anterior and posterior regions of the brain, and reduction of the intracranial SERP P160 waveform in the gyrus cingulus.

Paradoxically, there may be physiological reactivity to pain stimuli while the hypnotized Subject reports they are not consciously aware of pain. Posner’s proposal of two different attentional systems may account for why there is physiological reactivity concurrent with lack of awareness of pain. Posner suggested that the posterior brain is involved with engaging and disengaging attention while the anterior brain is involved in attention for action or effortful attention. “Thus, the posterior region is involved in space and time, the epicritic processes, whereas the anterior region is involved in comfort- discomfort, the protocritic processes (Pribram, 1991)” (p. 665).
In parallel, there appear to be two systems of pain involving the cortex, as revealed in positron emission tomography research. Also relevant is clinical data showing that “removal of the frontal or cingulate cortex in patients with intractable pain leads to the amelioration of distress while not eliminating sensory pain (Bouckoms, 1989)” (p. 665).
The author proposes a neuropsychophysiology of hypnotic analgesia based on Hilgard’s (1986) neodissociation theory of hypnosis, together with Pribram and McGuinness’ (1975, 1992) attention model. In this view, “Hilgard’s executive control system is the far frontal cortex ‘directing’ the inhibition of incoming painful stimuli” (p. 666) after determining that the somatosensory signal is ‘irrelevant.’
“Highly hypnotizable individuals (‘highs’) have greater attentional and disattentional abilities than low hypnotizable individuals (‘lows’). … Recent neuroimaging techniques (PET, SPECT, CBF) that assess regional brain metabolism have found no differences in waking conditions between low and highly hypnotizable individuals, but have consistently reported that only highs show increased cerebral blood flow during hypnosis, suggestive of enhanced cognitive effort (Crawford, Gur et al., 1993; Halama, 1989; Meyer, Diehl, Ulrich, & Meinig, 1989; Walter, 1992)” (p. 666).
The hippocampus appears to be involved as a gating mechanism in selective attention (Crowne, Konow, Drake & Pribram, 1972; Isaacson, 1982, Isaacson & Pribram, 1986; R. Miller, 1991; Pribram, 1991; Arnolds et al., 1980) This gating function may be promoted “through a cortico-hippocampal relay [that] transmits information by theta wave modulation and Hebbian synaptic modification so that there is selective disattention” (p. 667). The author suggests that hypnotic pain control may involve directing attention away from pain sensory signals.
Highly hypnotizable people generate more EEG theta than low hypnotizables whether they are hypnotized or not, and Crawford (1990) observed marked hemispheric shifts in theta when highs (but not lows) were attempting to control pain with hypnosis.
This paper reports on preliminary results of SERP studies of people given hypnotic analgesia suggestions to reduce electric shock stimulus evoked pain. The results were analyzed individual by individual, because group data obscured pronounced shifts in SERP patterns (e.g. habituation rates differed among Subjects). For highs, the SERP tended to be reduced, and the lower amplitudes were observed as early as the N100-P200 components. This did not occur for low hypnotizables.
Different kinds of mechanisms may be operative for high hypnotizables, however. “In over half of the high hypnotizable subjects the far frontal region (Fp1, Fp2) showed strong arousal during attention to pain, but during hypnotic analgesia there was a flattening out of the SERPs to the point they are hard to measure. By contrast, the more posterior SERPs (including F3 and F4), while reduced in amplitude, were still evident. The other half of highs showed little SERP activity in the far frontal region in either attend or disattend conditions, but substantial reductions of SERPs at all locations during hypnotic analgesia” (p. 670). Additionally, some of the highs evidenced a contingent negative variation (CNV) or a late 400-500 msec negativity in the far frontal region, which author is inclined to interpret as “a preparation for a response or for an inhibition of a response” (p. 670).
Case studies of two patients with intracranial electrodes and scalp electrodes recording SERPs are presented in support of the experimental data. The two female patients were diagnosed with obsessive compulsive disorder; one was highly hypnotizable and one was not. They received 30 moderately painful stimuli to the left middle finger under sequential conditions: waking attention, hypnosis with analgesia suggestions, and hypnosis with attention instructions. The highly hypnotizable patient reported significantly less pain during suggested analgesia, and that reduction in pain was associated temporally with reduction of SERP at P160 in the gyrus cingulus (and at no other recording sites). The ‘unhypnotizable’ patient showed no SERP changes. As an aside, the author notes that “Subsequent to the hypnotic analgesia, when the pain was attended to again during waking this patient showed a significant enhancement of the same positivity wave at Fz, as if there was a rebound effect (something we have also observed in some of our SERP subjects at the BRAINS Center)” (p. 674).

DePascalis, Vilfredo (1994). Event-related potentials during hypnotic hallucination. International Journal of Clinical and Experimental Hypnosis, 42 (1), 39-55.

Event-related potentials were elicited by visual stimulation and recorded at frontal, central, and posterior scalp sites so as to study the psychophysiological process associated with hypnotic hallucination. Subjects were screened using two measures of hypnotic susceptibility (Harvard Group Scale of Hypnotic Susceptibility, Form A and the Stanford Hypnotic Susceptibility Scale, Form C). Seven high and 9 low hypnotizable right-handed females participated in the experiment. Eight intermediate hypnotizable right-handed females served as controls. Peak amplitudes and latencies of P1, N1, P2, N2, and P3 components were compared in two hypnotic conditions (obtained by means of hypnotic suggestions): stimulus enhancement and stimulus elimination. High hypnotizable subjects displayed a significant attenuation of the P1 and N1 amplitudes of the evoked response while experiencing stimulus elimination. The effect for the P1 component was greatest at the posterior sites compared to that found at the anterior and central sites. A similar trend across condition was also observed for P3 peak amplitude, even though the Group x Condition interaction was only marginally significant (p <.07). during negative hallucination, P3 peak latency for high hypnotizables was shorter than that obtained during stimulus enhancement. This effect was more pronounced across the right hemisphere. These results are discussed in light of previous findings. 1993 Dabic-Jeftic, Mirjana; Barnes, Graham (1993). Event-related potentials (P300) during cognitive processing in hypnotic and non-hypnotic conditions. Psychiatria Danubina, 5 (1-2), 47-61. In this study authors investigated to find out if there were any specific changes of event related potentials in subjects before hypnosis, entering hypnosis, in deep hypnosis and leaving hypnosis, and to compare mental activities of subjects such as capability of correctly calculating and remembering the exact number of unexpected stimuli delivered by stimulator with their verbal or nonverbal reports during any of the conditions investigated. The methodology was of testing the cognitive evoked potentials elicited by auditive stimuli, using the oddball paradigm. Obtained results show that the most constant values of shortest latency and highest amplitudes of the cognitive waves, especially P300 were found during deep hypnosis. All five subjects in the investigation answered with the exact number of delivered target stimuli only after deep hypnosis. Conversely, in all other conditions their answers were approximate to the correct number of delivered target stimuli. (Author abstract.) NOTES 1: In this experiment, 5 adult volunteers were told to attend to one of two tones delivered through headphones. The tones were randomly delivered but one occurred 85% of the time (the 'frequent, non-target tone') and the other occurred 15% of the time (the 'rare, target tone'). The subjects were to notice, remember, and count the target tone. Measures were taken during five periods: pre-hypnosis, entering hypnosis, deep hypnosis, leaving hypnosis, and post-hypnosis. Some subjects had extensive hypnosis experience prior to the experiment; others had little. The EEG P300 wave was sensitive to condition. Latency of P300 was significantly shorter in deep hypnosis compared with other periods. Higher amplitude of P300 also occurred during deep hypnosis compared with other periods. (Notes taken from secondary reference, Ericksonian Newsletter.) Jutai, Jeffrey; Gruzelier, John; Golds, John; Thomas, Martin (1993). Bilateral auditory-evoked potentials in conditions of hypnosis and focused attention. International Journal of Psychophysiology, 15, 167-176. Brain event-related potentials (ERPs) evoked by auditory stimulation were used to study cerebral hemispheric activity during hypnosis. ERPs were recorded from bilateral central (C3 and C4) and temporal (T3 and T4) scalp locations in response to tone pips in 6 medium-high and 6 low-susceptible subjects in three conditions: baseline (tones only), hypnosis (tones plus hypnotic induction), and a focused attention control (tones plus a newspaper story read by the hypnotist). Task asymmetries were individually adjusted for baseline asymmetries. Responses from central locations did not differentiate hypnosis from focused attention for either group. The same was true of temporal locations for the low-susceptible group. The predominant temporal lobe pattern for both conditions and groups was larger left than right responses. The exception was the hypnosis condition for the medium-high susceptible group where there was an increase in responses in the right temporal lobe. Lyskov, E.; Juutilainen, J.; Jousmaki, V.; Hanninen, O.; Medvedev, S.; Partanen, J. (1993). Influence of short-term exposure of magnetic field on the bioelectrical processes of the brain and performance. International Journal of Psychophysiology, 14, 227-231. The influence of an extremely-low-frequency (ELF) magnetic field on the bioelectrical processes of brain and performance was studied by EEG spectral analysis, auditory-evoked potentials (AEP), reaction time (Roletaking) and target-deletion test (TDT). Fourteen volunteers were exposed for 15 min to an intermittent (1 s on/off) 45- Hz magnetic field at 1000 A/m (1.26 mT). Each person received one real and one sham exposure. Statistically significant increases in spectral power through alpha- and beta- bands, as well as in mean frequency of the EEG spectrum were observed after magnetic field exposure. Field-dependent changes of N1OO were also revealed. No changes in the amplitudes or latencies of the earlier peaks were observed. No direct effects on Roletaking, nor on TDT performance were seen. However, practice effects on Roletaking (decrease of Roletaking in the course of the test-sessions) seemed to be interrupted by exposure to the magnetic field. 1992 Miller, Scott D.; Triggiano, Patrick J. (1992). The psychophysiological investigation of multiple personality disorder: Review and update. American Journal of Clinical Hypnosis, 35, 47-61.