High Hypnotizability Research Articles

Internal and External Distraction in the Control of Cold-pressor Pain as a Function of Hypnotizabiliy

The effectiveness of different pain-distraction tasks was compared as a function of level of hypnotizability, using the cold-pressor pain-testing procedure. Selected high, medium, or low hypnotizable participants first underwent a 1-minute baseline immersion of a hand in ice water, with periodic pain ratings. Independent groups were then given 4-minute test immersions under one of five conditions. Analgesia suggestion and guided imagery were conceived to be internal distractors, whereas word memory and pursuit-rotor tasks were external distractors. Placebo-control groups were given permission to let their minds wander. All four experimental treatments reduced pain significantly for highly hypnotizable participants, compared to the control group, whereas none of the experimental treatments were effective for low hypnotizables. The different treatment instructions did not produce differnt preimmersion anxiety state ratings, so the treatment effects on pain ratings could not be explained in terms of their effects on anxiety. It appears that high hypnotizables are more effective than low hypnotizables at diverting attention to control pain, regardless of whether internal or external distractor tasks are used. Treatment effects on pain ratings did not change between 1 and 4 minutes of test immersion.

Multiple identities & false memories: a sociocognitive perspective

Preface - John F. Chaves and Bill Jones About the Author Introduction I. The Use of Hypnosis as a Therapeutic Tool Hypnosis: Mythology Versus Reality High Hypnotizability and Dramatic Behaviors Hypnotic Amnesia, Posthypnotic Response, and Brainwashing II. Creating False Memories Distortions of Memory The Seduction Theory: Old and New Versions Child Sexual Abuse and the Fate of Abuse Memories Hypnosis, Age Regression, and Memory Complex False Memories, Body Memories, and Hypnosis UFO Abduction: An Example of Complex False Memory The Experimental Creation of Multiplicity III. Multiple Identities in Other Cultures and Times Cross-Cultural Studies of Spirit Possession Historical Manifestations of Demonic Possession The Social Functions of Possession From Possession to Dual Consciousness From Dual Consciousness to Multiple Personality The History of Dissociation IV. The Theory of Multiple Personality Disorder Multiple Personality Disorder and Social Learning Correlates of Multiple Personality Disorder Child Abuse and Multiple Personality Disorder Multiple Personality Disorder, Recovered Memories, and Sociopolitical Considerations V. Conclusion Final Thoughts References Author Index Subject Index

P300 event-related-potential amplitudes and evoked cardiac responses during hypnotic alteration of somatosensory perception

Ten highly hypnotizable women and 10 women with low hypnotizability were tested in a sometosensory target detection task to evaluate the effects of hypnotic alterations of somatosensory perception on P3 peak amplitude and evoked cardiac response. Stimulus detection task consisted of standard and target electric stimuli delivered with a fixed foreperiod. The P3 peak amplitude of ERPs recorded from frontal, central and temporo-parieto-occipital (posterior) scalp sites and phasic heart rate deceleration response were compared in four conditions: (1) normal attention in waking state, (2) hypnotic obstuctive hallucination, (3) hypnotic attention, (4) hypnotic passive attention. High hypnotizable subjects demonstrated suppression of P3 peak amplitude to target stimuli in the left frontal and posterior scalp sites during hypnotic obstructive hallucination as compared to a normal attention condition. In this condition P3 suppression was paralleled by a smaller anticipatory heart rate deceleration response to probe stimulus onset. The P3 peak to standard stimuli was found significantly greater in low hypnotizable subjects than for those with high hypnotizability regardless of condition. These findings demonstrate that hypnotically induced obstructive hallucination to somatosensory stimuli involve alterations in neural and autonomic response and are consistent with a trait conception of hypnotizability.

On the interaction of hypnotizability and negative affect in chronic pain. Implications for the somatization of trauma.

The high risk model of threat perception predicts that high hypnotizability is a risk factor for trauma-related somatization. It is hypothesized that high hypnotizability can increase experimentally induced threat or negative affect, as measured by skin conductance level, in a linear or dose-response manner. This hypothesized interaction of hypnotic ability and negative affect was found in a consecutive series of 118 adult patients with chronic pain symptoms. Larger increases in skin conductance levels during cognitive threat were significantly related to higher levels of hypnotizability. In addition, individuals with high hypnotizability retained higher skin conductance levels than individuals with low hypnotizability after stress. The clinical implications of the interaction of hypnotizability and negative affect during threat perception and delayed recovery from threat perception are discussed in terms of cognitive mechanisms in the etiology and therapy of trauma-related dissociative disorders.

Simulation, surreptitious observation and the modification of hypnotizability: two tests of the compliance hypothesis

AbstractIn Experiment 1, two groups of subjects low in hypnotizability were administered the full Carleton Skills Training Package (CSTP) to enhance hypnotizability and two groups were given a partial version of the CSTP, which eliminates information aimed at teaching an active interpretation of suggestions. Half the subjects given the full CSTP and half given the partial CSTP were instructed to fake their way through the training and later hypnotizability post‐tests. Simulators in both the full and partial group exhibited equivalently high post‐test scores, but non‐simulators given the full CSTP attained higher post‐test scores than non‐simulators given the partial CSTP. These findings suggest that the partial and full CSTP contain equivalent compliance demands and that differences between these procedures in enhancing hypnotizability stems from the interpretational skills taught by the full CSTP. In Experiment 2, hypnotic post‐test responding was surreptitiously observed when subjects believed that they were alone. Simulators instructed to fake their way through the CSTP and the post‐test stopped responding when they believed they were alone. CSTP non‐simulators and subjects who attained high hypnotizability without training exhibited high levels of post‐test responding while alone. Together the findings of the two experiments indicate that compliance cannot account adequately for the hypnotizability enhancements induced by skill training. Copyright © 1996 British Society of Experimental and Clinical Hypnosis

Hypnotizability and traumatic experience: a diathesis-stress model of dissociative symptomatology

OBJECTIVE: The authors propose a diathesis-stress model to describe how pathological dissociation may arise from an interaction between innate hypnotizability and traumatic experience. METHOD: To support the proposition that pathological dissociation may reflect autohypnotic process, the authors highlight clinical and research data indicating parallels between controlled hypnotic dissociative states and uncontrolled pathological dissociative symptoms and summarize evidence of hypnotizability in persons with psychiatric disorders that manifest these symptoms. The authors present this evidence by examining dissociative symptomatology in four psychological domains: perception, behavior and will, affect, and memory and identity. In addition, modern cognitive and neuropsychological models of dissociation are briefly reviewed. RESULTS: Several lines of evidence converge in support of the role of autohypnosis in pathological dissociation. There is considerable evidence that controlled formal hypnosis can produce a variety of dissociations of awareness and control that resemble many of the symptoms in uncontrolled pathological dissociative conditions; and it is possible to discern in dissociative pathology the features of absorption, dissociation, and suggestibility/automaticity that characterize formal hypnotic states. There is also accumulating evidence of high levels of hypnotic capacity in all groups with dissociative symptomatology that have been systematically assessed. In addition, the widespread and successful therapeutic use of hypnosis in the treatment of many dissociative symptoms and conditions (and the potential for hypnosis to induce dissociative symptomatology) also supports the assumption that hypnosis and pathological dissociation share an underlying process. CONCLUSIONS: High hypnotizability may be a diathesis for pathological dissociative states, particularly under conditions of acute traumatic stress.

On the Edge of Science: Coping With UFOlogy Scientifically

(1996). On the Edge of Science: Coping With UFOlogy Scientifically. Psychological Inquiry: Vol. 7, No. 2, pp. 136-140.

EEG asymmetry and heart rate during experience of hypnotic analgesia in high and low hypnotizables

This study evaluates the effects of hypnotic analgesia and hypnosis on bilateral EEG activity recorded from frontal, central and posterior areas during three painful electrical stimulation conditions: waking, hypnosis/no-analgesia, hypnosis/analgesia. Eight high-hypnotizable and eight low-hypnotizable (right handed) subjects participated in the experiment. The following measures were obtained: pain and distress tolerance ratings; EEG spectral amplitudes for the frequency bands: δ (0.5–3.75 Hz), θ1 (4–5.75 Hz), θ2 (6–7.75 Hz), α1 (8–9.75 Hz), α2 (10–12.75 Hz), β1 (13–15.75 Hz), β2 (16–31.75 Hz), total band (0.5–31.75 Hz), ‘40-Hz’ (36–44 Hz); cardiac interbeat interval (ms); mid-frequency and high-frequency peaks from power spectral analysis of heart period variability. During hypnosis/analgesia, high hypnotizable subjects displayed significant reductions in pain and distress scores compared to hypnosis/no-analgesia and waking conditions. In each experimental condition these subjects displayed significant lower total and β1 amplitudes compared to low hypnotizables. High hypnotizables, on central and posterior recording sites, during both hypnosis/analgesia and hypnosis/no-analgesia conditions also showed total and delta EEG amplitude reductions in both hemispheres and a θ1 amplitude reduction in the left hemisphere. However, for total, delta and β1 bands in the hypnosis/analgesia condition the amplitude reduction was more pronounced in the right hemisphere as shown by hemispheric asymmetry in favor of the left hemisphere. Low hypnotizables, on posterior recording sites, displayed a delta amplitude reduction during hypnosis/no-analgesia and hypnosis/analgesia conditions. These subjects also showed, for all recording sites, a reduction in θ1 amplitude during hypnosis/no-analgesia compared to the waking condition. Lows, however, failed in evidencing amplitude differences between hypnosis/no-analgesia and hypnosis/analgesia conditions. During hypnotic analgesia the hemispheric asymmetry found in high hypnotizables was parallel to a significant reduction in the spectral mid-frequency peak of heart period variability which indicated a decrease in the level of sympathetic activity. In contrast, during hypnosis/no-analgesia the EEG amplitude reduction was not paralleled by a decrease in sympathetic activity.

Paired-Associate Learning and Recall of High and Low Imagery Words: Moderating Effects of Hypnosis, Hypnotic Susceptibility Level, and Visualization Abilities

Relationships between recall of low and high imagery paired-associate (P-A) words and hypnotic susceptibility, and the influence of hypnosis on recall as moderated by hypnotic level were examined. Subjects were assessed on 2 hypnotic susceptibility scales [Harvard Group Scale of Hypnotic Susceptibility; Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C)]. Forty-one low (0-4 SHSS:C) and 41 highly (9-12 SHSS:C) hypnotizable college students were assigned to 1 of 4 experimental groups: waking-hypnosis, hypnosis-waking, waking-waking, or hypnosis-hypnosis. Recall was significantly better for high than low imagery words. In the more sensitive within-subjects design, high hypnotizables recalled more P-A words during hypnosis than waking, and lows did not differ. In the between-subjects design, hypnotic level was not a moderator of performance during hypnosis. Low hypnotizables recalled more words in the within-subjects design. Visualization ability was a poor moderator of imagery-mediated learning. High imagery recall correlated significantly with Marks's (1973) Vividness of Visual Imagery Questionnaire (.25) and Paivio and Harshman's (1983) Individual Differences Questionnaire (IDQ) Verbal scale (.29), but not with the IDQ Imagery scale, the Mental Rotations Test (Vandenberg & Kuse, 1973), or the revised Minnesota Paper Form Board Test (Likert & Quasha, 1941).

Visual Perception of Area and Hypnotic Susceptibility

The visual perception of area of geometrical figures was compared for subjects of high and low hypnotizability in experiments with direct comparison of two different geometrical figures. The Stanford Hypnotic Susceptibility Scale (Form C) was used to assess subjects' hypnotizability. No differences between 17 highly hypnotizable and 10 low hypnotizable subjects were found. Present results were also compared with those previously obtained for subjects of unknown hypnotizability. The model based on the Image Function Theory proposed earlier to explain the errors in area estimation committed by subjects of unknown hypnotizability was confirmed as a general rule.

Zidovudine CNS effects in HIV-1 infection

The purpose of the present research was to find physiological and cognitive correlates of hypnosis, imaginative suggestibility and emotional experiences. After the administration of a standard hypnotic induction, the EEG and heart rate (HR) were recorded during self-generated happy and sad emotions using a relaxation condition as a control. Physiological recordings were also obtained during three eyes-open and eyes-closed baseline periods: (1) waking rest; (2) early-rest in hypnosis (just after the hypnotic induction); (3) late-rest hypnosis (at the end of hypnotic condition). EEG was recorded at frontal (F3, F4), central (C3, C4), and posterior sites (middle of O1-P3-T5 and O2-P4-T6 triangles). Using log transform of mean spectral amplitude, eight EEG frequency bands (4–44 Hz) were evaluated. High hypnotizable subjects, as compared to the lows, produced a higher theta1 amplitude (4–6 Hz) across both left- and right-frontal and right-posterior areas. These subjects also produced smaller alpha1 amplitude (8.25–10 Hz) over both left and right frontal recording sites. High suggestible subjects, during resting conditions, disclosed higher theta2 (6.25–8 Hz) and alpha1 amplitudes in eyes-closed as compared to an eyes-open condition than did low suggestible subjects. High suggestible subjects also showed, in hypnosis-rest condition, higher 40-Hz amplitudes (36–44 Hz) and HR activity than did low suggestible subjects. Hypnotizability and not suggestibility was found to moderate emotional processing: high hypnotizable individuals self-reported greater levels of emotional experiences than did low hypnotizables especially in terms of negative emotion. High hypnotizables, during processing of emotional material, also disclosed opposite 40-Hz hemispheric asymmetries over anterior and posterior regions of the scalp. These subjects during happiness showed an increased production of 40-Hz activity in the left frontal and central regions of the scalp, while during sadness they showed an increased activity in the right central and posterior regions. The hemispheric asymmetries for relaxation condition were similar, but less marked, to those obtained for happiness. No significant interactions involving both hypnotizability and imaginative suggestibility were found for physiological variables considered in this study. This demonstrates that hypnotizability and suggestibility reflect different underlying psychophysiological activities.

EEG reactivity and its functional significance for normal and abnormal behaviour

We evaluated the working hypothesis that the EEG activity associated to non-painful and painful stimuli in condition of waking state (no hypnotic procedure) was related to the hypnotizability level.Hypnotizability level was measured in 16 healthy subjects through the Italian version of the Stanford Hypnotic Susceptibility Scale (SHSS, score: 0–12). EEG data (56 electrodes) were recorded during non-painful and painful electrical stimuli applied to the left index finger. Cortical activity (vertex N1–P2 complex) was compared in subjects with low hypnotizability level (N = 8, SHSS:0–6) vs. subjects with high hypnotizability level (N = 8, SHSS:7–12).The amplitude of the N1–P2 complex was lower in the High-hypnotizability compared to the Low-hypnotizability group over primary sensorimotor cortex (C3 and C4 electrodes) and centro-parietal midline areas (Cz and Pz electrodes) for non-painful and painful stimuli. The SHSS showed a statistically significant negative correlation with the vertex N1–P2 complex at C3 and Cz (r = −0.5, p < 0.05) electrodes for non-painful stimuli.Compared to the Low-hypnotizability subjects, High-hypnotizability subjects showed a reduced cortical activity related to non-painful and painful stimuli.The results suggest a relationship between hypnotizability and cortical activity related to non-painful and painful stimuli in the condition of waking state (no hypnotic effect).

Enhanced Afterimage Persistence in Waking and Hypnosis: High Hypnotizables Report More Enduring Afterimages

This study investigated the moderating influences of hypnotic susceptibility level (high/low) and visuospatial skill level (high/low) on afterimage persistence in waking and hypnosis. All Ss were administered the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A; [1]), the Group Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C; [2]), and the Mental Rotations Test (MRT; [3]). In counterbalanced sessions of waking and hypnosis, 80 Ss (20 high/high, 20 high/low, 20 low/high, 20 low/low) were dark adapted for twenty minutes each, after which a brief flash of light was presented. Visuospatial skills, as measured by the MRT, did not significantly influence first afterimage intervals or afterimage durations. High hypnotizables reported significantly longer first afterimage intervals and afterimage durations in hypnosis than did low hypnotizables. High hypnotizables reported significantly longer first afterimage intervals, but not afterimage durations, in waking than did low hypnotizables. High hypnotizables reported significantly longer afterimage durations and first afterimage intervals in hypnosis than in waking. Low hypnotizables reported similar afterimage durations and first afterimage intervals in waking and hypnosis. Implications of these results for the ability of high hypnotizables to focus attention upon and maintain valid visual images are discussed.

Effect of Hypnotic Suggestion on the Delayed-Type Hypersensitivity Response

To determine whether individuals selected for good general health, high hypnotizability, and the ability to alter skin temperature under hypnotic suggestion can influence the delayed-type hypersensitivity (DTH) response to varicella-zoster (VZ) antigen under hypnotic suggestion. A blinded clinical trial using a repeated measures design with subjects serving as their own controls. Subjects were randomly assigned to undergo a predetermined sequence of four different experimental conditions, occurring at weekly intervals, with each condition including VZ skin testing: (1) hypnosis with suggestions to enhance the DTH response to VZ antigen; (2) hypnosis with suggestions to suppress the DTH response; (3) hypnosis with suggestions for relaxation only; and (4) skin testing without hypnosis. A National Institutes of Health-supported clinical research center in a teaching hospital. A stratified sample of 24 ambulatory, healthy, highly hypnotizable, volunteer college students selected for their above-average ability to alter skin temperature after hypnotic suggestions and their positive baseline responses to VZ antigen. There were 11 males and 13 females with a mean +/- SD age of 22 +/- 6 years. The mean +/- SD hypnotizability score (Harvard Group Scale of Hypnotic Susceptibility) was 11 +/- 1. Intradermal skin testing with VZ antigen (Mantoux method) and hypnotic suggestion. Areas of induration of the DTH response measured at 24 and 48 hours after injection of antigen. The area of the DTH response was not affected by the experimental interventions. The area of erythema was likewise unaffected. Our subjects were unable to alter their DTH responses using hypnotic suggestion.

Individual Variability in Muller-Lyer Illusion Difference Thresholds: Moderating Influences of Hypnotic Susceptibility in Waking and Hypnosis

This study investigated the differential influences of hypnotic susceptibility on Muller-Lyer illusion difference thresholds in waking and hypnosis using the psychophysical method of constant stimuli. As assessed by the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) and the Group Stanford Hypnotic Susceptibility Scale, Form C (GSHSS:C), sixteen high (scores = 9–12) and sixteen low (scores = 0–3) hypnotizables participated. In counterbalanced sessions of waking and hypnosis, each subject was sequentially exposed to 110 computer-generated Muller-Lyer illusion pairs of comparison stimuli and a standard stimulus. Difference thresholds for high and low hypnotizables did not differ significantly in waking, but were significantly lower for high than low hypnotizables in hypnosis. Difference thresholds were also significantly lower for high hypnotizables in hypnosis than in waking. Low hypnotizables performed similarly in waking and hypnosis.

Pseudomemory in hypnotized and simulating subjects.

High hypnotizable (n = 23) and low hypnotizable simulating (n = 13) subjects received pseudomemory suggestions. High hypnotizable and low hypnotizable simulating subjects were equally likely to pass the target noise suggestion during hypnosis and were also equally likely (high hypnotizables, 47.83%; low hypnotizable simulators, 64.29%) to report pseudomemories when tested for pseudomemory after instructions to awaken. As in previous research with task-motivated subjects, pseudomemory rate (high hypnotizables, 47.48%; low hypnotizable simulators, 46.15%) was not reduced by informing subjects that they could distinguish fantasy and reality in a nonhypnotic state of deep concentration. At final inquiry, after deep concentration, high hypnotizable and low hypnotizable simulating subjects' pseudomemories remained comparable (43.48% and 38.46%, respectively). Unlike previous research, high hypnotizable subjects did not report more unsuggested noises and more pseudomemories of novel sounds than did awake low hypnotizable simulating subjects. Pseudomemory reports were generally consistent with subjects' ratings of whether the hypnotist expected them to believe the sounds were real or imagined.

Event-Related Potentials During Hypnotic Hallucination

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.

EEG spectral analysis during hypnotic induction, hypnotic dream and age regression

EEG was recorded monopolarly at frontal (F 3, F 4), central (C 3, C 4) and posterior (in the middle of O 1-P 3T 5 and O 2-P 4-T 6 triangles) derivations during the hypnotic induction of the Stanford Hypnotic Clinical Scale (SHCS) and during performance following suggestions of hypnotic dream and age-regression as expressed in the before-mentioned scale. 10 low-hypnotizable and 9 highly-hypnotizable and right-handed female students participated in one experimental session. Evaluations were Fast-Fourier spectral analyses during the following conditions: walking-rest in eyes-open and eyes-closed condition; early middle, and late phases of hypnotic induction; rest-hypnosis in eyes closed condition; hypnotic dream and age regression. After spectral analysis of 0 to 44 Hz, the mean spectral amplitude estimates across seven Hz bands (theta1, 4–6 Hz, theta2, 6–8 Hz; alpha1, 8–10 Hz; alpha2, 10–13 Hz; beta1, 13–16 Hz; beta2, 16–20 Hz; beta3, 20–36 Hz) and the 40-Hz EEG band (36–44 Hz) for each experimental condition were extracted. In eyes-open and -closed conditions on walking and hypnosis highly-hypnotizable subjects produced a greater 40-Hz EEG amplitude than did low hypnotizable subjects at all frontal, central and posterior locations. In the early and middle hypnotic induction highly-hypnotizables displayed a greater amount of beta3 than did low hypnotizables and this difference was even more pronounced in the left hemisphere. With posterior scalp recordings, during hypnotic dream and age regression, high hypnotizables displayed, as compared with the rest-hypnosis condition, a decrease in alpha1 and alpha2 amplitudes. This effect was absent for low hypnotizables. Beta1, beta2 abd beta3 amplitudes increased in the left hemisphere during age regression for high hypnotizables; low hypnotizables, in contrast, displayed hemispheric balance across imaginative tasks. High hypnotizables during the hypnotic dream are also displayed in the right hemisphere a greater 40-Hz EEG amplitude as compared with the left hemisphere. This difference was even more evident for posterior recording sites. This hemispheric trend was not evidenced for low hypnotizable subjects. Theta power was never a predictor of hypnotic susceptibility, 40-Hz EEG amplitude displayed a very high main effect ( p < 0.004) for hypnotizability in hypnotic conditions by displaying a greater 40 Hz EEG amplitude in high hypnotizables with respect to lows.

Surreptitiously observed hypnotic responding in simulators and in skill-trained and untrained high hypnotizables.

Low-hypnotizable Ss (LHs) administered cognitive skill training exhibited substantially higher posttest hypnotizability than LHs administered no treatment. Next, the Ss in these 2 conditions as well as Ss who attained high hypnotizability without training and LHs instructed to fake hypnosis (i.e., simulators) were individually tested for hypnotizability twice while their responses were recorded by a hidden camera. In the individual session, Ss were first tested for hypnotizability while alone and then tested again in the presence of an experimenter. The skill-trained Ss and high-hypo notizable controls attained equivalent (high) hypnotizability scores with the experimenter both absent and present

Hypnosis and Attention Deficits After Closed Head Injury

In a controlled study of patients attending a concussion clinic because of ongoing postconcussion symptoms, attention deficits were recorded in the head-injured group for the aspects of alertness, assessed by the Continuous Performance Test (CPT), and processing capacity, assessed by a version of the Paced Auditory Serial Addition Test (PASAT). Selective attention was intact. Hypnotizability was assessed by the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), with normal means and standard deviations found in both the concussed and control groups. There was a significant correlation, however, between HGSHS:A scores and PASAT scores in the concussed group only. The results of this preliminary study suggest that slower processing capacity after a closed head injury may predict higher hypnotizability and that hypnosis could be an appropriate rehabilitation technique for these patients who present with postconcussion symptoms.