Low Hypnotizables Research Articles

Hypnotic alteration of somatosensory perception.

Effects of hypnotic alterations of perception on amplitude of somatosensory event-related potentials were studied in 10 highly hypnotizable subjects and 10 subjects with low hypnotizability. The highly hypnotizable individuals showed significant decreases in amplitude of the P100 and P300 waveform components during a hypnotic hallucination that blocked perception of the stimulus. When hypnosis was used to intensify attention to the stimulus, there was an increase in P100 amplitude. These findings are consistent with observations that highly hypnotizable individuals can reduce or eliminate pain by using purely cognitive methods such as hypnosis. Together with data from the visual system, these results suggest a neurophysiological basis for hypnotic sensory alteration.

40-Hz EEG asymmetry during recall of emotional events in waking and hypnosis: differences between low and high hypnotizables

Sixteen high and thirteen low hypnotizable women, who had participated in our previous study (De Pascalis et al., 1987), were enrolled in a hypnotic session. After the hypnotic induction they were requested to recollect 2 positive and 2 negative personal life experiences. In our previous study subjects performed similar tasks in a waking-state. Hypnotizability was evaluated the first time with the Harvard Group Scale of Hypnotic Susceptibility (Form A) and, a second time, individually, with the Standford Hypnotic Susceptibility Scale (Form C). The State Trait Anxiety Inventory,. Maudsley Personality Inventory, and Tellegen Absorption Scale were administered. Upper-trapezius electromyogram (EMG) and bilateral electroencephalogram (EEG) activities within the 35–45 Hz band were recorded. Self-report rating scores for vividness of visual imagery and emotional feeling of the material recalled were evaluated. The 40-Hz EMG amplitude and the left and right hemisphere 40-Hz EEG densities were obtained. The data collected in hypnosis were compared with those in the waking-state. High hypnotizables, with respect to the lows, displayed significantly lower 40-Hz EEG density in the rest condition. High hypnotizables, while they were in hypnosis, showed an increase of 40-Hz EEG density during emotional recall compared with rest periods. In contrast, low hypnotizables, after hypnotic induction, showed no density change during tasks compared to the rest conditions. Different hemispheric trends were found between groups. Highs showed an increase of 40-Hz EEG density over both hemisphere during positive emotions and a density increase in the right and a density reduction in the left during negative ones. This hemispheric trend was found in waking and hypnotic conditions although in the hypnotic condition more pronounced hemispheric patterns were observed. The Tellegen Absorption Scale was found positively related to hypnotizability and with the level of 40-Hz density increase on the right hemisphere during emotional tasks. High hypnotizables, with respect to the lows, were able to access affects more readily. They also showed a greater hemispheric specificity in waking and hypnotic conditions.

Are hypnotically induced pseudomemories resistant to cross-examination?

Two experiments examined the effects of hypnotic procedures in response to interrogation and crossexamination in subjects who viewed a simulated robbery. Experiment 1 found that hypnotic and nonhypnotic leading interrogations were equally likely to produce misattributions and misidentification of mug shots. Moreover, under cross-examination subjects who had been given an hypnotic interrogation and those given nonhypnotic interrogations were equally likely to disavow their earlier misattributions and misidentifications. In both hypnotic and nonhypnotic treatments high hypnotizables were more likely than low hypnotizables to misattribute characteristics during interrogation and to disavow earlier misattributions during cross-examination. In Experiment 2 high hypnotizables given a cross-examination that legitimated their earlier errors as honest mistakes and that enabled them to disavow earlier testimony without discrediting themselves (hidden observer treatment) showed the highest and most consistent rates of disavowel. A stringent cross-examination that implied that subjects had been careless or dishonest during interrogation produced the lowest rates of disavowel.

EEG asymmetry during covert mental activity and its relationship with hypnotizability.

Abstract Parieto-occipital EEG was recorded bilaterally while 20 high and 20 low hypnotizable Ss performed, in the eyes-closed condition, 2 covert right-hemisphere tasks (visual long-term memory and fantasy) and 2 covert left-hemisphere tasks (multiplication and verbal long-term memory). Ss were not, however, hypnotized during any aspect of the psychophysiological testing. After each task, Ss rated orally their degree of involvement in the tasks. The integrated amplitude alpha, the alpha density, and the alpha ratio as a measure of hemispheric asymmetry, were evaluated. Finally, the proportion of relatively greater right activation periods during right-hemisphere tasks minus the analogous proportion during left-hemisphere tasks was used as index of hemispheric specificity. The high hypnotizable Ss showed significantly higher alpha amplitude than the low hypnotizables; the alpha amplitude was correlated with hypnotizability, while the alpha density was not. The alpha amplitude of the right hemisphere durin...

Hemispheric activity of 40 Hz EEG during recall of emotional events: differences between low and high hypnotizables

This study evaluates individual differences in hypnotizability as reflected in waking-state hemispheric engagement during recollection of 3 positively and 3 negatively valenced personal life events. The State-Trait Anxiety Inventory, Maudsley Personality Inventory, Tellegen Absorption Scale and Harvard Group Scale of Hypnotic Susceptibility (Form A) were administered. Electromyogram (EMG) and bilateral electroencephalogram (EEG) activities within the 40-Hz band were recorded during rest and task conditions in 22 high and 21 low hypnotizable women. Self-report rating scores for vividness of visual imagery and emotional feeling of the material recalled were evaluated. The 40-Hz EMG amplitude and both hemisphere 40-Hz EEG densities were obtained. A 40-Hz EEG ratio, as a measure of hemispheric asymmetry, and a hemispheric specificity index were also computed. High hypnotizables showed significantly lower 40-Hz EEG density than low hypnotizables in all experimental conditions. The relationship between lateralization of 40-Hz EEG and emotional processing was moderated by hypnotizability. High hypnotizables, with respect to rest condition, showed an increase of density over both left and right hemispheres during two of the three positive emotional tasks, while they showed a depressed activity over the left and an increased activity over the right during negative emotional tasks. Low hypnotizables, on the other hand, did not exhibit differential hemispheric patterns that could be attributed to different emotional valences. The high group showed greater hemispheric specificity in the predicted direction than the low group. High subjects exhibited greater ratings of absorptive ability and emotional feeling than low subjects. Anxiety and EMG levels did not differ between groups. EMG was dependent on the type of emotion which showed greater activity in the negative emotion condition compared with the positive one.

Dichotic listening and hypnotizability: variability in ear preference.

28 right-handed, English-speaking subjects were administered two tests, Stanford Hypnotic Susceptibility Scale-Form C and a whole-word dichotic listening test. The latter was given in both waking and hypnotized states. Subjects of low hypnotizability showed the usual right-ear advantage in both waking and hypnotized states. Subjects of high hypnotizability showed a different pattern of ear advantage: half of the group-showed left-ear advantage in the waking state but all showed right-ear advantage in the hypnotized state. Results are interpreted to show that for subjects of high hypnotizability, the narrowed attention characteristic of hypnosis produces the expected lateralizing effect. Subjects of low hypnotizability show a consistent right-ear preference in both the hypnotized and nonhypnotized conditions. The results suggest that much of the atypical ear preference shown in dichotic listening experiments may be associated with the variability in cognitive states found in persons of high hypnotic susceptibility.

Temporal organization and hypnotic amnesia using a modification of the Harvard Group Scale of Hypnotic Susceptibility.

Abstract The Harvard Group Scale of Hypnotic Susceptibility, Form A (Shor & E. Orne, 1962) was modified to permit better assessment of amnesia and changes in temporal organization during amnesia. First, a baseline measure of recall was obtained before administration of the amnesia suggestion. Second, on the recall trial following cancellation of the suggestion, Ss recalled everything they could remember. Amnesia was assessed by comparing recall during the suggestion with recall before it and after it was cancelled. Temporal organization was assessed by correlating the order of item administration with Ss' recall orders. Hypnotic susceptibility and amnesia were independently related to temporal organization. Overall, high hypnotizable Ss organized less than medium or low hypnotizables, and amnesics showed less temporal organization than nonamnesics, but neither of these variables interacted with recall trial. The results are discussed in terms of recent theories of hypnotic amnesia.

Eidetic-like Imagery in Hypnosis: Rare but There

The production of eidetic-like imagery during hypnosis in subjects with high but not low hypnotizability was supported in three separate experiments using nonfakable stereograms (Julesz, 1971; Gummerman, Gray, & Wilson, 1972). In Experiment 1, 6 (25%) of 24 stringently chosen, high hypnotizables were able to perceive one of the superimposed stereograms (presented monocularly) during conditions of standard hypnosis or hypnotic age regression, or under both conditions, but not during waking. In Experiments 2 and 3, low and high hypnotizables were presented stereograms in an alternating, monocular fashion (one-half to each eye). In Experiment 2, 10% of the high hypnotizables perceived one or more stereograms in hypnosis or age regression, but not during waking. In Experiment 3, none of the 17 low hypnotizables reported correct stereograms, but 6 of the 23 high hypnotizables (26%) did. Relationships between imagery performance and visuo-spatial abilities were investigated. Results support the general hypothesis that hypnosis enhances imaginal processing of information to be remembered that is a literal or untransformed representation.

The efficacy of direct versus indirect hypnotic induction techniques on reduction of experimental pain.

Abstract The cold pressor test was used to investigate the efficacy of Rapid Induction Analgesia, a new, indirect hypnotic technique introduced by J. Barber (1977). Rapid Induction Analgesia was compared with traditional hypnosis, relaxation, suggestion without an induction, and a no-treatment control in Ss of high and low hypnotizability. Only traditional hypnosis was found to significantly reduce S's reported pain when compared to the control group Ss, and Rapid Induction Analgesia was not found to be an effective treatment in this study, in contrast to J. Barber's earlier findings.

Hypnotic susceptibility as related to gestalt closure tasks.

The investigation was concerned primarily with the relationship of gestalt closure tasks to hypnotizability on a test of the hypothesis that the more highly hypnotizable do better on a task of holistic visuospatial functioning than those less responsive to hypnosis. Several other cognitive tasks were included: visualization, disembedding of hidden figures, and syllogistic reasoning. Sex differences were inconsistent in the four studies reported. In Study 1 (22 male and 20 female university students), high hypnotizables scored significantly higher than low hypnotizables on the gestalt closure tasks, but there were no significant correlations between hypnotizability and the other cognitive tasks. In Study 2 (25 male and 25 female university students) and Study 3 (41 male and 37 female university students), females showed significant correlations between hypnotic susceptibility and gestalt closure scores. In Study 4 (37 male and 27 female high school students), a significant correlation between hypnotic susceptibility and gestalt closure was found for males. The results are consistent with studies of different types of cognitive functioning (hemispheric preference, creativity, attentional distribution, imaginative involvement, and absorption), all indicating differences in cognitive abilities associated with high hypnotizability.

Hysterical psychosis and hypnotizability

The very existence of hysterical psychosis as a diagnostic entity has been questioned as part of the general difficulty in defining both hysteria and psychosis. However, several recent investigations have documented a syndrome that usually involves brief and intense periods of psychotic behavior, generally with graphic decompensation, severe environmental stress, and rapid recompensation, in individuals with other hysterical features. The authors assert that such a syndrome does exist as a clinical entity and that the differential diagnosis can be facilitated by using a standardized measure of hypnotic trance capacity. They hypothesize that patients with hysterical psychosis are highly hypnotizable, while those who are schizophrenic and psychotic have low hypnotizability. The authors review the literature and present two case examples.

Hypnotizability, creativity and the role of effortless experiencing.

Abstract Creative people and highly hypnotizable people describe their experience of finding creative solutions or responding to hypnotic suggestions as “effortless.” It is suggested that receptiveness to subconscious work accounts for the experience of effortlessness in both tasks. An experiment using 32 high and low hypnotizable men and women was designed to explore the hypothesis that the aptitude for such effortless experiencing accounts for the relationship found between creativity and hypnotizability. Analyses of variance indicate highly significant effects of level of hypnotizability on composite scores reflecting effortless experiencing of several tasks and creativity. Intercorrelations of these indices are about .60. As predicted, effortless experiencing accounts for much of the relationship between high versus low hypnotizability and composite creativity. The role of imagery vividness and of absorption in both hypnotizability and creativity were also explored.

Effects of hypnotizability and visualizing ability on imagery-mediated learning.

Abstract The Ss selected for hypnotizability and visualizing ability were tested for their performance on an imagery-mediated, paired-associates task in which the stimulus materials were varied in imagery and concreteness. Imagery and concreteness showed significant main effects and an additive interaction facilitating learning. Neither hypnotizability nor visualizing ability showed main effects, thereby contradicting the conjecture that those 2 factors would facilitate imagery-mediated learning. However, high hypnotizable Ss learned more high imagery words than the low hypnotizables, and visualizing ability was shown to interact with word concreteness. It is concluded that the effects of hypnotizability and visualizing ability on verbal learning are, at least in part, a function of the content of the words to be learned.

EEG Alpha‐Hypnotizability Correlations: A Review

ABSTRACTExperimental investigations of the relationships between EEG alpha indices and hypnotic susceptibility are reviewed. The literature is characterized as indicating that the simple alpha‐hypnotizability correlation does not exist in the general population. When such correlations are found, they are usually due to complex patterns which result in non‐representative subject pools when subjects are non‐naive volunteers. When subjects are invited to participate in experiments, significant correlations are not found.The implications of these conclusions are threefold: 1) The research on the relationship between EEG alpha and hypnotizability can now center on describing the mechanisms by which volunteer samples yield such correlations. 2) Researchers should be aware that subject selection methods can be the primary determinants of significant results. 3) Experiments based on the assumption that there is no alpha‐hypnotizability correlation in the population can yield information on the differences in cognitive ability between high and low hypnotizables.

EEG alpha: lateral asymmetry related to task, and hypnotizability.

ABSTRACTOccipital EEG alpha (8‐13 Hz) was recorded separately from the right and left hemispheres of 26 right‐handed subjects during analytic (verbal and numerical) tasks, spatial (imagery) tasks, a music task, and a hypnotic susceptibility scale. An alpha laterality score was derived by computing the percent difference in the amplitude of alpha in the two hemispheres. This laterality score was significantly different between the analytic and spatial tasks, and between an eyes‐open baseline and an eyes‐open measurement during hypnotic amnesia. Because the spatial tasks used in this study are considered “easier” than the analytic or music tasks, the role of task difficulty provides some ambiguity in interpretation.Highly hypnotizable subjects showed significantly more alpha activity (compared to low hypnotizables) in all conditions (both outside hypnosis and within it) except for the eyes‐open baseline and the eyes‐open measurement following the release of amnesia. No differences were found between low‐ and high‐hypnotizables in the laterality measure. This suggests that the lateral asymmetry of alpha is a function of task rather than of any particular cognitive style that may characterize the hypnotically susceptible. That high hypnotizables showed higher amplitudes of alpha, however, suggests that the overall production of alpha may be positively related to the particular cognitive style that characterizes the person who is able to experience hypnotic phenomena.

SPECIFIC MOTOR RESPONSE DURING SLEEP TO SLEEP-ADMINISTERED MEANINGFUL SUGGESTION: AN EXPLORATORY INVESTIGATION.

Complex meaningful suggestions were given during various stages of physiological sleep as defined by EEG monitoring to 4 Ss high and 4 Ss low in hypnotizability. All the high hypnotizability Ss gave accurate behavioral responses while remaining asleep, but none of the low hypnotizability Ss did so. Specific response to sleep-administered suggestion was obtained only during Stage 1 periods.