Because sleep learning (“hypnopedia”) has been extensively practiced in Russia and Eastern Europe, especially for language learning, the author investigated language learning with nine subjects. (Hoskovec, 1966, and Rubin, 1968, have reviewed the hypnopedia literature, which suggests that only “suggestible” subjects respond; it is not clear whether “suggestible” refers to hypnotizable, or whether expectation of success is cultivated by information given in the waking state.) The nine Ss had responded to the suggestions at least twice while remaining asleep, had no waking recall of the suggestions, but were given pre-sleep instructions (increasing expectancy) that they would learn during sleep.
The verbal association material (“A is for apple; P is for palace;” etc.) was given during EEG sleep stages 2, 4, and REM. (Eight letter-word stimuli pairs were given, two per sleep stage whenever possible.) When they awakened, Ss were asked to check “any familiar word” on a list of 10 words beginning with the letter A, with the letter P, etc. So the probability was .10 for each of the eight lists that they might check one correct word by guessing. They also responded to two dummy lists containing letter-word pairs not used during sleep.
None of the dummy list words were checked, whereas 28% of the administered words were correctly checked; also, Ss selected the correct letter (without identifying the word and with instructions not to “guess”) in an additional 17% of all lists. Words were rarely recalled from Stages 2 and 4, but Ss often recognized letters from those stages. False positives (incorrectly recalled words or letters) was almost never observed. Furthermore, no control Subjects (people who had not received a presleep set that they would recall) recalled any words correctly.
It was observed that whenever words presented during REM were later recalled, a transient slower frequency alpha (10.25 Hz vs. 9.64 Hz, p<.01) had been evoked within 30 sec after the presentation of the stimuli during sleep.
Total recall of words correlated with the Harvard Group Scale of Hypnotic Susceptibility .69 and the Stanford individually administered scale .42, for the 7 Ss administered hypnotizability tests.
The author concludes that under optimal conditions, sleep learning of relatively easy material can occur with subsequent waking recall.
Fischer, Donald G.; Elnitsky, Sherry (1990). A factor analytic study of two scales measuring dissociation. American Journal of Clinical Hypnosis, 32, 201-207.
The present study was designed to investigate the construct validity of dissociation. We administered the PAS and the DES to 507 male (48%) and female (52%) undergraduate students. Factor analysis on each scale separately showed that neither the PAS nor the DES adequately measures the three dimensions hypothesized to underlie dissociative experience. For both scales, a single factor emerged as replicable and reliable. Use of the scales, in their present form, therefore, should be limited to a single dimension representing disturbances in affect-control in the case of the PAS and disturbances in cognition-control if the DES is used at least with normal populations. Analysis of the combined items showed that the scales are measuring conceptually different but statistically correlated dimensions of dissociation. Further development of both scales is desirable, and further research should investigate the effect of different response formats on the internal structure of the scales.
scales is desirable, and further research should investigate the effect of different response formats on the internal structure of the scales.
The stated purpose of this study was to investigate the internal structure of the Perceptual Alterations Scale (PAS) and the Dissociative Experiences Scale (DES) using a large sample from a normal population.
"Sanders (1986) conceived of dissociation as a personality trait that is characterized by modification of connections between affect, cognition, and perception of voluntary control over behavior, as well as modifications in the subjective experience of affect, voluntary control, and perception. She chose items from the MMPI to represent this trait. Bernstein and Putnam (1986), utilizing the DSM-III definition of dissociation, constructed items from information derived from interviews with patients and clinicians to represent a number of different types of dissociative experiences" (0. 202).
"The PAS (Sanders, 1986) is a 27-item scale; subjects respond by checking one of the following categories using a 4-point Likert format: never, sometimes, frequently, almost always. The items related to modifications of regulatory control, changes in self- monitoring, concealment from self and others, and modifications of sensory, perceptual, and affective experiences.
"The DES (Bernstein & Putnam, 1986) contains 28 items. Subjects indicate the percentage of time they experience the feelings or behavior described by the items on a 10- point scale. The items related to the experience of disturbances in identity, memory, awareness and cognition, and feelings of derealization or depersonalization" (pp. 202- 203).
Results were as follows. The one-factor solution for the PAS accounted for 18.5% of the total variance.; 11 of the 28 items did not load significantly on the factor. The one-factor solution for the DES accounted for 26.3% of the total variance; 7 of the 28 items did not load significantly on the factor.
"The 3-factor solution obtained by Sanders (1986) for the PAS was not replicated. An obvious reason for the different is that principal factor extraction was used in the present study, whereas principal components extraction was utilized by Sanders. ... Even when principal components analysis is performed on the present data, however, there are difficulties with the 3-factor solution" (pp. 204-205).
"All of the criteria suggest that a single factor best represents the latent structure of dissociative experience as measured by the PAS and DES. Although the total amount of variance accounted for is low, the one-factor solutions for both scales are interpretable, replicable, and have high internal consistency. The items for the PAS appear to represent primarily the affect and control dimensions, whereas those for the DES represent the cognitive dimension" (pp. 205-206).
"Overall, both scales contain similar items, although the DES has more items relating to disturbances in memory and altered perception of time (i.e., cognition), whereas the PAS has more items reflecting specific disturbances in identity and control. It appears, therefore, that the scales are measuring conceptually separate but statistically correlated dimensions of dissociation" (p. 206).
Friedman, Howard; Taub, Harvey A.; Sturr, Joseph F.; Monty, Richard A. (1990). Hypnosis and hypnotizability in cognitive task performance. British Journal of Experimental and Clinical Hypnosis, 7 (2), 103-107.
Gwynn, Maxwell I.; Quigley, Celia; Perlini, Arthur; Glatt, Richard; Spanos, Nicholas P. (1990, August). Eyewitness testimony: Effects of hypnotic interrogation and witness preparation. [Paper] Presented at the annual meeting of the American Psychological Association, Boston.
There is notable absence of empirical research on the effects of witness preparation on subsequent testimony. The present study investigates the separate and combined effects of hypnotic recall procedures and witness preparation on subjects' confidence in, and maintenance during cross-examination, of mug-shot identifications.
Session 1: Subjects viewed a 65 second videotape of a mock crime involving a shooting. The offender in this video was a male approximately 40-50 years old, whose face was partially obscured by the brim of a baseball cap.
Subjects were then taken individually to another room, where a second experimenter presented them with a series of five photographic mug shots. Half of the series contained the mug shot; the other did not. Subjects indicate if any portrayed the offender and then to rate their confidence in their identification.
Subjects for Session 2 were randomly assigned to one of two conditions:
Hypnotic condition ... followed by "reliving" instructions modeled after Reiser's procedures used in training police detectives.
Nonhypnotic condition ... Each subject was then presented with the mug shot lineup and rated their confidence as in Session 1 with the same second experimenter.
Subjects who in Session 2 identified any mug shot as portraying the offender returned about one week after for a mock courtroom appearance. Subjects were randomly assigned to either a "prepared" condition, or a "nonprepared" condition, with the restriction of equal numbers of offender-present vs. offender-absent lineups and hypnotic vs. nonhypnotic subjects in each condition ... The subject-witness was questioned by the third same experimenter under direct examination and then cross-examined by a fourth experimenter in the role of defense attorney.
Subjects in the prepared condition were given pointers concerning their courtroom appearance. These pointers included counseling to answer all of the questions fully, to speak in complete sentences, and to present themselves confidently.
The videotapes of the subjects' testimonies were then shown to independent blind raters who rated the degree of confidence displayed by the subject-witness at two points, first after direct examination, and again after cross-examination.
To summarize the results: 1) As in a number of previous studies, eyewitness confidence was unrelated to mug shot identification accuracy. 2) The use of hypnotic techniques as practiced by many police investigators did not lead to an increase in the frequency or accuracy with which subjects identified a mug shot as portraying a previously viewed offender. 3) Again consistent with previous research, the use of hypnosis did lead to an increase in eyewitness confidence, without a corresponding increase in accuracy, and this confidence increase was correlated with pretested levels of hypnotic susceptibility. 4) Contrary to the speculation of researchers such as Orne, Laurence & Perry, hypnotic procedures _did not_ lead to the creation of unshakable witnesses who were impervious to cross-examination. And, 5) The usual practice of pre-trial preparation of witnesses _did_ lead to a resistance of witnesses to be broken down under cross-examination.
In conclusion, the key factor found to affect eyewitness confidence and mug shot identification was _not_ the use of hypnotic memory enhancement techniques, but rather the usual practice of pre-trial witness preparation.
Hajek, P.; Jakoubek, B.; Radil, T. (1990). Gradual increase in cutaneous threshold induced by repeated hypnosis of healthy individuals and patients with atopic eczema. Perceptual and Motor Skills, 70, 549-550.
Gradual increase in cutaneous pain threshold was found in healthy subjects and patients with atopic eczema during repeated hypnotic sessions with specific suggestions. This increase was less in the former than in the latter group. Repeated threshold measurements did not influence the threshold. The analgesic effect outlasted the hypnotic sessions by several months. It could be, however, suddenly reduced by appropriate hypnotic suggestion.
Cutaneous pain threshold was measured in "time in seconds from onset of heat source of defined size, distance from skin, and temperature, to subjective threshold percept of pain" (p. 549). Used two symmetrical locations on both forearms, at healthy areas of the skin. Ten hypnotic sessions were induced in each S three times weekly, each lasting one hour.
Suggestions were the following type: "The "conduction of switch to the brain is interrupted." Your "immunologic system will digest the damaged skin cells like a shark."
Subjects were 14 healthy subjects and 13 patients with atopic eczema treated for years with the usual medications, unsuccessfully or with complications.
There was gradual increase in cutaneous pain threshold across the 10 sessions, especially for the patient group. Control experiments with repeated threshold measurements in repeated sessions without hypnosis showed no changes.
"Time of increases in cutaneous pain threshold was associated with improvement of atopic eczema. Both effects correlated significantly (r = 0.8) with hypnotizability as measured by the Stanford scale" (pp. 549-550).
"In 9 patients without further hypnotic sessions a slow spontaneous decay of the cutaneous pain threshold was observed during a 17-mo. period. Special experiments performed with six repeatedly hypnotized healthy subjects showing increased thresholds did prove, however, that the cumulative analgesic effect could be reduced to control values immediately by using the hypnotic suggestion that the 'skin sensitivity returns to normal values.'
"These results suggest a close association between hypnosis and activation and/or deactivation of endogenous analgesic systems (irrespectively whether they are of opioid or nonopioid nature)" (p.550)
Kihlstrom, John F.; Schacter, Daniel L.; Cork, Randall C.; Hurt, Catherine A.; Behr, Steven E. (1990). Implicit and explicit memory following surgical anesthesia. Psychological Science, 1, 303-306.
Paired associates were presented to 25 surgical patients following the induction of anesthesia by thiopental, vecuronium, and isoflurane. Postoperative testing (immediately or after two weeks) showed no free recall for the list; nor was there significant cued recall or recognition, compared to a matched control list. However, a free-association task showed a significant priming effect on both immediate and delayed trials. At least under some conditions, adequate surgical anesthesia appears to abolish explicit, but not implicit, memory for intraoperative events.
anesthesia appears to abolish explicit, but not implicit, memory for intraoperative events.
Labelle, L.; Laurence, J. R.; Nadon, R.; Perry, C. (1990). Hypnotizability, preference for an imagic cognitive style, and memory creation in hypnosis. Journal of Abnormal Psychology, 99, 222-228.
1989
The author notes a current trend toward viewing multiple personality disorder (MPD) and its variants as a form of chronic post-traumatic stress disorder based solely on exogenous childhood trauma, and cautions against prematurely reductionistic hypotheses. He focuses on Kluft's Third Etiological Factor, which includes the various developmental, biological, interpersonal, sociocultural, and psychodynamic shaping influences and substrates that determine the form taken by the dissociative defense. He hypothesizes a credibility continuum of childhood and contemporary memories arising primarily from exogenous trauma at one end, and endogenous trauma (stemming from intrapsychic adaptational needs) at the other. The author offers alternative multidetermined explanations for certain unverified trauma memories that currently are being accepted and validated as factual experiences by many therapists. He describes some potentially deleterious effects of validating unverified trauma memories during psychotherapy, and recommends that the MPD patients' need for unconditional credibility be responded to in the same manner as other transference-generated productions.
Lindsay, D. S.; Johnson, M. K. (1989). The eyewitness suggestibility effect and memory for source. Memory and Cognition, 17, 349-358.
Examined the possibility that eyewitness suggestibility reflects failures of the processes by which people normally discriminate between memories derived from different sources. Misled and control subjects were tested either with a yes/no recognition test or with a "source-monitoring" test designed to orient Ss to attend to information about the sources of their memories. The results demonstrate that suggestibility effects obtained with a recognition test can be eliminated by orienting Ss toward thinking about the sources of their memories while taking the test. Findings indicate that although misled Ss are capable of identifying the source of their memories of misleading suggestions, they nonetheless sometimes misidentify them as memories derived from the original event. The extent to which such errors reflect genuine memory confusions (produced, for example by lay judgment criteria) or conscious misattributions (perhaps due to demand characteristics) remains to be specified.
1988
Boeke, S.; Bonke, B.; Bouwhuis-Hoogerwerf, M. L.; Bovill, J. G.; Zwaveling, A. (1988). Effects of sounds presented during general anaesthesia on postoperative course. British Journal of Anaesthesia, 60, 697-702.
In a double-blind, randomized study, patients undergoing cholecystectomy were administered one of four different sounds during general anaesthesia: positive suggestions, nonsense suggestions, seaside sounds or sounds form the operating theatre. The effect of these sounds on the postoperative course was examined to assess intraoperative auditory registration. No differences were found between the four groups in postoperative variables.
Postoperative course was evaluated by 5 variables: pain, nausea and vomiting, evaluation by nursing staff, subjective well-being, and duration of postoperative hospital stay. From the chart they used amount of postoperative analgesia, volume of nasogastric suction or drainage and fluid lost through vomiting over 6 days post-operatively; duration of postoperative hospital stay was registered after discharge. See p. 699 for details, including wording of questions. They cite their own earlier study that got positive results, and explain the difference as possibly due to use of only male voices on tapes, lack of difference in the sounds on tapes in this study, insensitivity of outcome measures (patients stayed longer in first study than in this one), and sample too small in this study (106).
Boeke et al. (1988) report that this double-blind, randomized study of positive suggestions, noise or sounds from the operating theatre presented to 3 groups of patients undergoing cholecystectomy during general anaesthesia had positive results for older patients. patients > 55 years who received positive suggestions had a significantly shorter postoperative hospital stay than the other patients in this age category.
Council, James R.; Loge, D. (1988). Suggestibility and confidence in false perceptions: A pilot study. British Journal of Experimental and Clinical Hypnosis, 5, 95-98.
Subjects received audiotaped instructions implying that they would perceive increases in odor or heaviness while comparing stimuli in a sensory-judgment task. Stimuli were actually indiscriminable. Subjects pretested as higher or
indiscriminable. Subjects pretested as higher or lower in hypnotizability performed the task in either hypnotic or non-hypnotic conditions. In both treatments, greater hypnotizability was associated with more perceived changes in the stimuli and greater confidence in the reality of those perceptions. Results support a general factor underlying suggestibility in hypnotic and nonhypnotic situations. The findings are discussed in relationship to false confidence effects reported in hypermnesia research.
Dywan, Jane (1988). The imagery factor in hypnotic hypermnesia. International Journal of Clinical and Experimental Hypnosis, 36, 312-326.
Week-long repeated recall attempts were used as baseline against which to assess the effects of hypnosis on the recall of pictures. Hypnosis increased errors for all Ss but especially for high hypnotizables. In Experiment 1, dividing Ss on the basis of imagery ability had the same effect on recall as dividing them on the basis of hypnotic ability. In Experiment 2, imagery ability was found to interact with hypnosis in mediating the level of error during waking trials. Results do not support the claim that hypnosis enhances recall, but they do suggest that further study is needed to clarify the role that imagery ability plays in recall patterns over time
Author reviews research indicating that introduction of confident errors is a reliable finding in hypnosis-memory research, and notes that the role of imagery ability has not as yet been examined even though imagery is viewed as important to memory functioning. She also reviews the imagery- hypnotizability correlation literature.
EXPERIMENT 1 involved 54 Ss screened by Harvard Scale and SHSS:C, divided into highs (7-12) and lows (1-6) by SHSS:C. Stimuli were 60 black and white line drawings. There were 3 baseline trials in the lab; Ss were then given 6 envelopes, each containing a 60 blank item recall sheet, and asked to complete one each day and return it via campus mail. (When unable to recall more items, they were asked to draw a line under the last item recalled and then use “educated guesses.” ) After a week of repeated recalls, Ss in the hypnosis condition were told they would be able to ‘see’ the slides appear before them; in the task motivating condition Ss were informed about such things as context dependent recall, the importance of focused attention, and the importance of good recall for forensic investigations.
Results were analyzed for increase in recall over the cumulative number of correct items recalled. Neither hypnotizability nor visual imagery ability influenced the cumulative baseline measures. High hypnotizable Ss produced a small but significantly greater increase in new, correct information during hypnosis than other Ss, but also made 3 times as many errors.
Dividing Ss by imagery score produced similar results. That is, people with very good imaging ability reacted in the same manner as the highly hypnotizable Ss: in hypnosis they increased the number of items they were willing to call a memory but also increased the number of errors.
EXPERIMENT 2 differed from Experiment 1 in that Ss were selected for hypnotic ability and imagery ability so that both would be adequately represented. (The high hypnotizable – low visual imagery group is a group that hasn’t been represented much in earlier research, and the author notes that those Ss are rather difficult to locate. ) The task motivation condition was not used, based on results of Experiment 1. Ss who were low on hypnotizability and imagery ability served as the controls.
Ss were told that they could be either in a hypnosis condition or a control condition but actually all Ss received a hypnotic induction. (This is like the London- Fuhrer, 1961, research design, which goes on the assumption that low hypnotizables do not enter into hypnosis even though they are exposed to an induction. Thus, hypnotic effects are not assumed for lows in the hypnotic condition and they become “controls.”)
Results of correct and error recall over the baseline week were analyzed. There was no difference in correct recall as a function of hypnotic ability or visual imagery ability. However, there was a main effect for visual imagery ability and for hypnotizability, and a significant interaction between trials, for cumulative errors over the baseline week.
Effects of hypnosis were weaker than in Experiment 1 but followed same pattern. Those Ss most likely to have been hypnotized (highs) produced slightly more correct information than lows, and showed a greater increase in errors than lows. However high and low visualizers did not differ in response to hypnosis for correct information or for errors.
Since there was an interaction between hypnotic ability and visual imagery ability for error rate during waking trials, the author tested for the interaction during hypnosis. Using a 2 x 2 ANOVA with new errors as the dependent measure; no interaction was found. Hypnotic ability was therefore responsible for determining Ss’ responses in the hypnosis condition. Author attributes the effect to being hypnotized rather than to individual differences in hypnotizability or to context effects.
all Ss received a hypnotic induction. (This is like the London- Fuhrer, 1961, research design, which goes on the assumption that low hypnotizables do not enter into hypnosis even though they are exposed to an induction. Thus, hypnotic effects are not assumed for lows in the hypnotic condition and they become “controls.”)
Results of correct and error recall over the baseline week were analyzed. There was no difference in correct recall as a function of hypnotic ability or visual imagery ability. However, there was a main effect for visual imagery ability and for hypnotizability, and a significant interaction between trials, for cumulative errors over the baseline week.
Effects of hypnosis were weaker than in Experiment 1 but followed same pattern. Those Ss most likely to have been hypnotized (highs) produced slightly more correct information than lows, and showed a greater increase in errors than lows. However high and low visualizers did not differ in response to hypnosis for correct information or for errors.
Since there was an interaction between hypnotic ability and visual imagery ability for error rate during waking trials, the author tested for the interaction during hypnosis. Using a 2 x 2 ANOVA with new errors as the dependent measure; no interaction was found. Hypnotic ability was therefore responsible for determining Ss’ responses in the hypnosis condition. Author attributes the effect to being hypnotized rather than to individual differences in hypnotizability or to context effects.
DISCUSSION includes the author’s delineation of differences between the two experiments that might explain differences in results. The increase in errors that was observed may be due to increased fluency in producing items under hypnosis (Sheehan & Tilden, 1984, 1986) or to a shift in reporting criterion (e.g., M. T. Orne, Soskis, Dinges, & E. C. Orne, 1984).
“Both high and low hypnotizable Ss produced more memories in the task- motivating condition, and low hypnotizables are not totally immune from the effect in the hypnotic context. What the report-criterion hypothesis does not explain is the reason why the memory reports of high hypnotizable Ss are differentially affected by task demands (e.g., task-motivating instructions versus hypnosis in Experiment 1) nor why hypnotized Ss so often seem surprised by the ease with which information seems to be ‘recalled’ during hypnosis . An alternative hypothesis is that being hypnotized results in a shift to a more imagistic style of information processing. The enhanced vividness of items generated during the retrieval process may convince Ss that these items must have been part of the original stimulus presentation (Dywan, 1985).
“Whatever the mechanisms might be, it is clear that the hypnotic effect is the result of an interaction between contextual factors and pre-existing characteristics of the individual. Moreover, these same mechanisms would likely be at work when hypnosis is actually used in the forensic situation, where the pressure to retrieve information could be more acute than what can be mustered in the experimental context. This should cause some concern because the differential increase in errors did not occur only for the relatively small proportion of Ss who were very high in hypnotic ability. The ‘high’ hypnotizable group in these experiments consisted of Ss of moderate to high levels of hypnotic ability and so the results can be generalized to at least one-half the population” (p. 323).
“In summary, it would seem that any pressure for Ss to increase their recall– whether it be repeated trials, task-motivating instructions, or hypnotic suggestion–results in higher levels of output and lower levels of accuracy. Repeated recall attempts lead to increases in recall and in errors. Some Ss (viz., those with high levels of hypnotic ability and low levels of imagery ability) are particularly prone to producing false-positive responses over the course of repeated recall attempts. When Ss are pressed to recall more information, they all try to do so by increasing their output and this increased output is usually accompanied by an increase in error. When hypnosis is introduced, however, those Ss who are hypnotizable show a differential increase in output. The amount of new correct information retrieved by hypnotized Ss is small and not a highly reliable phenomenon. The increase in errors that occurs in the recall of hypnotized individuals, however, is a substantial and highly reliable effect. Irrespective of how many errors were made as a function of repeated recall attempts, hypnosis can be counted on to increase errors over and above the increases in errors that occur when Ss are not hypnotized. Further work is needed to identify the mechanisms involved in the hypnotic distortion of recall. The role that imagery ability might have in the context of waking and hypnotic recall has not been resolved and this also presents an interesting problem for future study” (pp. 323-324).
Gudjonsson, Gisli H. (1988). The relationship of intelligence and memory to interrogative suggestibility: The importance of range effects. British Journal of Clinical Psychology, 27 (2), 185-187.
60 normal adults and 100 adult psychiatric patients completed a suggestibility scale and the Wechsler Adult Intelligence Scale (WAIS). Clear range effects of IQ and memory were evident in their relationship with suggestibility
Kingsbury, Steven J. (1988). Hypnosis in the treatment of posttraumatic stress disorder: An isomorphic intervention. American Journal of Clinical Hypnosis, 31, 81-90.
Reviews literature on hypnosis treatment for PTSD and presents a rationale, based on the type of symptoms presented (blunting vs intrusions). Case presentations are provided.
“Several types of physiological processes may underlie dissociation. State- dependent learning, in which that learned during drug-induced alterations in consciousness may only be recalled during later similar alterations, is believed to be dependent upon hippocampal mechanisms (Gerrien & Chechile, 1977).The relationship of state-dependent learning to hypnosis has remained at the level of theory (Hilgard, 1977; Rossi, 1986). A second possible explanatory construct suggests everyday experience is primarily (but not exclusively) mediated by verbal, dominant hemisphere functioning. The images and sets mediating hypnosis, PTSD, and other forms of dissociation may be mediated by analogic processing and the nondominant hemisphere (Carter, Elkins, & Kraft, 1982; Galin, 1974; Hilgard, 1977; Watzlawick, 1978)” (p.83).
Kumar, V. K.; Pekala, Ronald J. (1988). Hypnotizability, absorption, and individual differences in phenomenological experience. International Journal of Clinical and Experimental Hypnosis, 36, 80-88.
The phenomenological effects associated with a baseline condition of eyes- closed and a hypnotic induction condition were compared across individuals of differing absorption capacity and hypnotizability. The results indicated that individuals of differing absorption capacity and hypnotizability reported different intensities of phenomenological experience
during the baseline eyes-closed condition. The induction further augmented intensity differences for low, medium, and high absorption and hypnotizable Ss, but more so for high (and medium) than low hypnotizable Ss. The results support both a trait and state interpretation of hypnotizability, and highlight the importance of the interaction between these factors on the resulting hypnotic experience of S.
Based on a review of relevant literature, the authors predicted that (1) during hypnosis and a baseline condition (eyes-closed), high absorption and high hypnotizable Ss will report the phenomenological effects at greater intensity relative to low absorption and low hypnotizable Ss, respectively; (2) hypnotic induction will be associated with increased absorption; greater alterations in awareness and experience; and decreased volitional control, rationality, and memory; (3) phenomenological intensity differences (hypnosis compared to eyes-closed) will be significantly greater for high than for low hypnotizable Ss.
They used the Phenomenology of Consciousness Inventory (PCI) developed by Pekala (1982), which is a 53 item self-report instrument that is completed retrospectively in reference to a preceding stimulus condition. The PCI measures the following dimensions and subdimensions: internal dialogue; self-awareness; state of awareness; imagery (amount, vividness); positive affect (joy, sexual excitement, love); negative affect (anger, fear, sadness); altered experience (time sense, body image, perception, unusual meanings); attention (absorption, direction); memory; rationality; volitional control; and arousal.
The 217 Ss were administered the Tellegen Absorption Scale, then sat quietly with eyes closed for four minutes, then completed the PCI, Form 1, relative to that 4-minute period. They were administered a slightly shortened version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A); before the posthypnotic suggestion and amnesia suggestion they experienced another 4-minute silent period during which they were told to ‘continue to experience the state you are in right now.’ After the HGSHS:A they completed PCI, Form 2, in reference to the silent period during the HGSHS:A, before they completed the 11-point questionnaire on the HGSHS:A.
Subjects who did not have reliable PCI response forms were removed from the sample, leaving 173 Ss who were divided into high, medium, and low Absorption groups, and high, medium, and low hypnotizability groups. The statistical analysis employed MANOVA on intensity scores for first the major PCI dimensions and then the 14 subdimensions using Conditions (eyes closed, hypnosis) and Groups. There were significant main and interaction effects. Subsequent ANOVAs for each (sub)dimension, Conditions by Hypnotizability Groups (2 x 3) were then performed.
Hypnosis “was associated with significantly less positive affect (joy, sexual excitement, love); negative affect (anger, sadness); visual imagery (amount, vividness); self-awareness, internal dialogue, rationality, volitional control, and memory; and significantly more altered experience (time sense, perception) and altered state of awareness.
“Significant main effects for Hypnotizability Groups were found for positive affect (joy, love); altered experience (body image, time sense, perception, meaning); attention (direction, absorption); self-awareness; altered state of awareness; rationality; volitional control; and memory
“Post-hoc comparisons for the eyes-closed condition revealed that high relative to low, hypnotizables reported significantly greater alterations in body image, time sense, meaning, and altered state of awareness. Medium hypnotizable Ss, compared to low hypnotizables, reported significantly increased alterations in body image and state of awareness.
“Post-hoc comparisons for the eyes-closed condition revealed that high relative to low, hypnotizables reported significantly greater alterations in body image, time sense, meaning, and altered state of awareness. Medium hypnotizable Ss, compared to low hypnotizables, reported significantly increased alterations in body image and state of awareness.
Geiselman, R. Edward; Machlovitz, Helen (1987). Hypnosis memory recall: Implications for forensic use. American Journal of Forensic Psychology, 1, 37-47.
Examines 38 major published experiments (1930-1985) on hypnosis memory recall. Concludes that differences in experimental methodology significantly predict the success versus failure of hypnosis aided recall and remarks that, “Even if forensic hypnosis aids in the solution of only a small percentage of cases, it is still a valuable tool from the perspective of law enforcement.” As Tarasoff has balanced the right of the victim to enjoy protection from violence with the patient-litigant’s right to confidentiality, so too does the increased acceptance of hypnotically induced testimony go toward redressing in part the uneven balance between the slender compensations afforded the innocent victim of violent crime and the multiple constitutional protections and indemnities enjoyed by criminal perpetrators in our judicial system.
Goldmann, Les (1987, October). Ways of maximizing patient memory for events during anesthesia. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Los Angeles.
Reported a series of experiments: 1. Under atropine, we did not get an orienting response to things having to do with the operation, but did get an orienting response to jokes, dogs barking, and the name of a polite anesthetist. 2. Replicated the research by Bennett and didn’t get ear pulling response. 3. Studied cardiac patients. Gave subjects a pre-anesthesia speech of importance [of hearing under anesthesia? Notes here are not clear.] and a chin touch suggestion that was successful. 7 of 30 subjects gave reports of recall – usually recalled something of particular interest to them. These 7 subjects appeared more anxious postoperatively than previously. 4. Recognition study: Pre-op “IQ” test. Gave subjects answers to the questions while they were under anesthesia, and postoperatively they had better performance than previously. 5. Recall study, double blind. Interviewer learned something about the patient, and told them something about what was learned about the patient during anesthesia e.g., You have a lovely garden. After surgery they were hypnotized by someone who did not know what information was given, and then recall for information “heard” under anesthesia was tested. 6. 10 female patients who were good hypnotic subjects, all received the same statement under anesthesia, that they would believe for a moment that they had green hair. During the interview, one said she was fascinated by green things, one wanted to go home and wash her hair.
Kihlstrom, John F. (1987). The cognitive unconscious. Science, 237, 1445-1452.
Contemporary research in cognitive psychology reveals the impact of nonconscious mental structures and processes on the individual’s conscious experience, thought, and action. Research on perceptual-cognitive and motoric skills indicates that they are automatized through experience, and thus rendered unconscious. In addition, research on subliminal perception, implicit memory, and hypnosis indicates that events can affect mental functions even though they cannot be consciously perceived or remembered. These findings suggest a tripartite division of the cognitive unconscious into truly unconscious mental processes operating on knowledge structures that may themselves be preconscious or subconscious.
1986
American Medical Association Council on Scientific Affairs (1986). Scientific status of refreshing recollection by the use of hypnosis. International Journal of Clinical and Experimental Hypnosis, 34, 1-12.
The Council finds that recollections obtained during hypnosis can involve confabulations and pseudomemories and not only fail to be more accurate, but actually appear to be less reliable than nonhypnotic recall. The use of hypnosis with witnesses and victims may have serious consequences for the legal process when testimony is based on material that is elicited from a witness who has been hypnotized for the purposes of refreshing recollection.
The Council finds that recollections obtained during hypnosis can involve confabulations and pseudomemories and not only fail to be more accurate, but actually appear to be less reliable than nonhypnotic recall. The use of hypnosis with witnesses and victims may have serious consequences for the legal process when testimony is based on material that is elicited from a witness who has been hypnotized for the purposes of refreshing recollection.
Davidson, Thomas McCabe (1986, January). Recall organization and volitional/non-volitional experiencing in posthypnotic and intrahypnotic amnesia: Inattention versus dissociation hypotheses (Dissertation, University of Waterloo). Dissertation Abstracts International, 47 (7), 3103-B.
“Two studies are reported which seek to evaluate the relative merits of two differing hypotheses concerning the cognitive processes underlying suggested hypnotic amnesia. The inattention hypothesis maintains that amnesia effects are produced when subjects volitionally divert attention from relevant retrieval cues so that recall is inefficient. The dissociation position is that
amnesic subjects are prevented from utilizing normally relevant retrieval cues by a dissociative barrier that blocks access to target memories — a forgetting over which subjects experience no volitional control. The two hypotheses were evaluated by means of a selective amnesia suggestion in the recall organization paradigm. “In the first experiment, high, medium, and low hypnotic susceptible subjects were administered either hypnotic induction or task-motivating instructions. Results indicated that there was no disorganization of amnesia trial recall or forgetting of words not targeted for amnesia, contrary to predictions from the inattention hypothesis. “In the second experiment, high hypnotizable subjects received the selective amnesia suggestion in both posthypnotic and intrahypnotic conditions. Intrahypnotic subjects were also separated into one group that received a ten second interval between the administration of the amnesia suggestion and the amnesia trial, and another group that had a delay between the suggestion and the amnesia trial equivalent to the posthypnotic group. Eight subjects who had testified that they were volitionally amnesic on a pre- screening amnesia test were also included in the posthypnotic condition. Again, the results indicated no recall disorganization or reduction in recall of words not targeted for amnesia. Subjects also uniformly provided evidence that their amnesia was experienced as non-volitional. There was, however, evidence that some amnesiacs were aware during the amnesia trial of the specific category targeted for amnesia. “The most important finding of both experiments is that subjects may attend to normally relevant retrieval cues and yet continue to evidence amnesia. The evidence is therefore consistent with the dissociation hypothesis, but disconfirms the inattention account of hypnotic amnesia. It appears that the selective amnesia context effectively prevents the successful use of volitional forgetting strategies. (Abstract shortened with permission of author)” (p. 3103).
Laurence, Jean-Roch; Nadon, Robert; Nogrady, Heather; Perry, Campbell (1986). Duality, dissociation, and memory creation in highly hypnotizability subjects. International Journal of Clinical and Experimental Hypnosis, 34, 295-310.
The present paper reports an initial attempt to create a pseudomemory in a group of highly hypnotizable individuals. It was found that for approximately 50% of Ss tested, recall of a specific event was modified when Ss integrated hypnotically suggested material which then posthypnotically was believed to be veridical. This modification in a previously reported memory was linked to a particular cognitive style found in high hypnotizable Ss, namely dual cognitive functioning. Ss reporting duality in hypnotic age regression, and, to a lesser extent, the hidden observer effect, were found to be the most prone to accept a suggested memory as real. These findings suggest the need to emphasize the importance of a cognitive-phenomenological approach to hypnosis and hypnotizability.
1985
Acosta, Enrique; Crawford, Helen J. (1985). Iconic memory and hypnotizability: Processing speed, skill or strategy differences?. International Journal of Clinical and Experimental Hypnosis, 33, 236-245.
The purported relationship between hypnotizability and speed of information transfer from iconic to short-term memory was studied in a comparison of 12 low and 12 high hypnotizable Ss. As in Ingram, Saccuzzo, McNeill, and
Ss. As in Ingram, Saccuzzo, McNeill, and McDonald (1979), high hypnotizable Ss showed less interference from a visual mask in the report of a briefly presented item than did low hypnotizable Ss when the mask delays were predictable. When the delay of the mask could not be anticipated, however, differences between high and low hypnotizable Ss disappeared. It is suggested that differences in information processing related to hypnotizability may be due to differences in strategy, skills, or other factors, rather than underlying information processing speed.
Hypnosis may require concentrative or selective attention, which usually is measured by self-report (e.g. Absorption) or by experimental measures. Several investigations indicate that high hypnotizable people are better than low hypnotizables at focusing on a task and ignoring extraneous information (Brown, Crawford, Smith, Leu, & Brock, 1983; Graham & Evans, 1977; Karlin, 1979; Miller, 1975; Wallace, 1979; Wallace, Garrett, & Anstadt, 1974; Wallace, Knight, & Garrett, 1976). One way to study attentional processes is through the effect of presenting a mask (e.g. $$$$$) shortly after presenting a stimulus (e.g. ABCDE). Ingram (1979) found that highs had faster information processing, but that might be due to anticipation bias associated with the method of limits employed. This study uses both an ascending method of limits, like Ingram, and a condition in which the mask delays were presented randomly within another block of trials.
RESULTS
“While the present study replicated Ingram et al.’s (1979) findings when an ascending method of limits was used (the same used by Ingram et al.) differences were not found in processing when ISIs were presented randomly. Thus, these results suggest that high and low hypnotizable Ss do not differ in their information transmission rates, but rather they may differ in other aspects which mediate performance in this task” (pp. 241- 242).
“Several lines of evidence point towards strategy or skill differences between high and low hypnotizable Ss as a possible explanation for the present findings. First, it was found that when Ss could anticipate the mask delay (the ascending condition), high hypnotizable Ss outperformed the low hypnotizables. When this anticipation was controlled, as in the random condition, the two groups did not differ when the data were scored by serial position. When the data were scored by a free recall scheme, there was a nonsignificant trend for high hypnotizable Ss to score higher than did the low hypnotizables. This trend suggests that high hypnotizable Ss may be more willing to guess, and to guess more accurately than low hypnotizables, when they have partial information about a letter, and/or they may have greater skill in perceiving incomplete information. The latter suggestion finds indirect support from Crawford (1981) who reported that high hypnotizable Ss can process fragmented stimuli (Gestalt Closure tests, see Thurstone & Jeffrey, 1966), significantly better than can low hypnotizables. High imagers have been shown also to perform significantly better than low imagers in Gestalt Closure tasks (Ernest, 1980). At a speculative level, given that recent research has suggested that iconic memory may be a right hemisphere phenomenon (e.g. Cohen, 1976, but also see DiLollo, 1981), and high hypnotizable Ss outperform low hypnotizables on certain right hemisphere tasks (e.g. Crawford, 1981), it may be asked if the trends found with the free recall scoring scheme in the present study might be a reflection of differential right hemisphere processing. Such a hypothesis could be investigated in future research by comparing the performance of high and low hypnotizable Ss, as possibly moderated by visuo-spatial ability, for stimuli presented to the left versus the right visual hemifield (Ernest, 1983).
“A second set of evidence in favor of strategy differences was found in Saccuzzo et al. (1982) which was published after the data for the present experiment were collected. In the Saccuzzo et al. (1982) paper, which was an extension and replication of Ingram et al. (1979), the same mask delay was used throughout a 10-trial block. The order of the blocks (i.e., the mask delays) was random. Thus, while S did not know which mask delay was used in the first trial of a block, the remaining 9 trials were the same and could be anticipated. During the first session, high hypnotizable Ss outperformed the low hypnotizables, but these differences disappeared on the second testing session. These results suggest that practice may have affected performance, rather than any underlying information processing speed differences” (pp. 242-243).
1985
Bennett, Henry L.; Davis, H. S.; Giannini, Jeffrey A. (1985). Non-verbal response to intraoperative conversation. British Journal of Anesthesiology, 57, 174-179.
In a double-blind study, 33 patients (herniorraphy, cholecystectomy and orthopedic) were randomly assigned to either suggestion or control groups. Under known clinical levels of nitrous oxide and enflurane or halothane anesthesia, suggestion patients were exposed to statements of the importance of touching their ear during a postoperative interview. Compared with controls, suggestion patients did touch their ear (tetrachoric correlation 0.61, P <0.02). test, U (Mann-Whitney frequently more so did they and Coe, William C.; Yashinski, Edward (1985). Volitional experiences associated with breaching posthypnotic amnesia. Journal of Personality and Social Psychology, 48 (3), 716-722. Highly responsive hypnotic subjects classified as having control over remembering (voluntaries) or not having control over remembering (involuntaries) during posthypnotic amnesia were compared during posthypnotic recall. Subjects rerated their voluntariness after the experiment. Two contextual conditions were employed (2 x 2 design): a lie detector condition meant to create pressure to breach amnesia and a relax control condition. In contrast to earlier findings, the recall data showed that both voluntary and involuntary subjects breached under the lie detector condition compared with their counterparts in the relax condition; however, the degree of breaching was not great in any condition. The results are discussed as they relate to studies attempting to breach posthypnotic amnesia and characteristics of the voluntary-involuntary dimension. Eich, Eric; Reeves, John L.; Katz, Ronald L. (1985). Anesthesia, amnesia, and the memory/awareness distinction. Anesthesia and Analgesia, 64, 1143-1148. Several studies have shown that surgical patients cannot consciously recall or recognize events to which they had been exposed during general anesthesia. Might evidence of memory for intraoperative events be revealed through the performance of a postoperative test that does not require remembering to be deliberate or intentional? Results of the present study, involving the recognition and spelling of semantically biased homophones, suggest a negative answer to this question and imply that intraoperative events cannot be remembered postoperatively, either with or without awareness. question and imply that intraoperative events cannot be remembered postoperatively, either with or without awareness. "In this experiment, we attempted to apply the distinction between memory and awareness of memory to the question of whether adequately anesthetized and apparently unconscious patients can register and retain what is said in their presence during surgery. Prior research relating to this question has focused, for the most part, on the ability of postoperative patients to recall or recognize a specific item....The inference need not be drawn, however, that 'patients in so-called surgical planes of anesthesia cannot hear' (15, p. 89) or that anesthetized patients cannot encode and store in memory events that transpire during their surgery. The possibility remains that even though the effects of memory for intraoperative events may not--and probably cannot--be revealed in postoperative tests of retention that require remembering to be deliberate or intentional, such effects might be evident in the performance of tests that do not demand awareness of remembering. "To explore the possible dissociation between memory and awareness of memory for intraoperative events, we modeled our experiment after a recent neuropsychological study by Jacoby and Witherspoon (5)" (p. 1143). "...it appears that the prior presentation of a word has a substantial impact on its subsequent interpretation and spelling, regardless of whether or not the word is correctly classified as 'old' in a later test of recognition memory" (p. 1144).