Rejected 3 9 8 12 —————————————————————————————— Note. Group A = hypnotized, influenced, not offered reward.
Group B = hypnotized, influenced, offered reward.
Group C = not hypnotized, influenced, offered reward.
Group D = not hypnotized, not influenced, offered reward.
In the Discussion, the authors wrote, “Because the only variable among these groups was the reward, a reasonable conclusion from the findings is that pseudomemories manifested by the subjects were (for the most part) not actual memory distortions. Presumably, the reward provided the subjects in Group B an incentive to ‘report the truth’ and a disincentive to give biased reports on the basis of the perceived expectations of the social or experimental context. Thus these data suggest that pseudomemory effects or the occurrence of the pseudomemory phenomenon among highly hypnotizable subjects can be minimized by providing a motivation to subjects to give unbiased reports.
“A major implication of these findings is that researchers should control for response bias resulting from perceived social demands or from leading test designs when they conduct pseudomemory research. Of further concern is the fact that a number of researchers contend that hypnotic interrogation of eye-witnesses can greatly facilitate the creation of pseudomemories (Levitt, 1990; Loftus, 1979; Orne, 1979; Putnam, 1979), and therefore hypnosis either should not be allowed in the courtroom or should be strictly controlled. Yet in light of our findings, response bias may be a confound in pseudomemory research, and thus researchers need to be cautious when making inferences to specific situations from data obtained in an experimental setting.
“Despite the existence of a confound of (unmeasured) differences in hypnotizability between the two groups, there was no significant difference between Group B and the control group (Group D). This suggests that if response bias is controlled for, there may not be significant differences in manifestation of pseudomemories between highly hypnotizable subjects and subjects representative of the general population. However, further research is needed in order to address this question” (pp. 76-77).

Ofshe, Richard J. (1992). Inadvertent hypnosis during interrogation: False confession due to dissociative state; mis-identified multiple personality and the satanic cult hypothesis. International Journal of Clinical and Experimental Hypnosis, 40, 125-156.

Induction of a dissociative state followed by suggestion during interrogation caused a suspect to develop pseudo-memories of raping his daughters and of participation in a baby-murdering Satanic cult. The pseudo-memories coupled with influence from authority figures convinced him of his guilt for 6 months. During this time, the suspect, the witnesses, and all the evidence in the case were studied. No evidence supported an inference of guilt and substantial evidence supported the conclusion that no crime had been committed. An experiment demonstrated the suspect’s extreme suggestibility. The conclusion reached was that the cult did not exist and the suspect’s confessions were coerced- internalized confessions. During the investigation, 2 psychologists diagnosed the suspect as suffering from a dissociative disorder similar to multiple personality. Both psychologists were predisposed to find Satanic cult activity. Each concluded that the disorder was due to “programming” by the non-existent Satanic cult.

Sheehan, Peter W.; Statham, Dixie; Jamieson, Graham A. (1991). Pseudomemory effects over time in the hypnotic setting. Journal of Abnormal Psychology, 100 (1), 39-44.

Highly (n=36), moderately (n=26), and low (n=48) susceptible Ss were administered either hypnosis or waking instruction to examine the hypothesis that pseudomemory will occur for hypnotic Ss as long as 2 weeks after suggestions are given for accepting false events. Accuracy and confidence of memory were measured for all ss, and memory was examined for free recall, structured recall, and recognition. Results indicated persistence of pseudomemory for the 2-wk period for both highly and moderately susceptible ss. Data highlighted the multifaceted operation of skill, contextual, and state instruction factors, and a hypothesis that ambiguity of communication when suggestion is delivered plays a part in the maintenance of pseudomemory over time is offered for further testing.

Supreme Court of the United States (1990). Vickie Lorene Rock, Petitioner v. Arkansas, on writ of certiorari to the Supreme Court of Arkansas [June 22, 1987]. International Journal of Clinical and Experimental Hypnosis, 38 (4), 219-238.

The popular belief that hypnosis guarantees the accuracy of recall is as yet without established foundation and, in fact, hypnosis often has no effect at all on memory” (p. 232). “Three general characteristics of hypnosis may lead to the introduction of inaccurate memories: the subject becomes ‘suggestible’ and may try to please the hypnotist with answers the subject thinks will be met with approval; the subject is likely to ‘confabulate,’ that is, to fill in details from the imagination in order to make an answer more coherent and complete; and, the subject experiences ‘memory hardening,’ which gives him great confidence in both true and false memories, making effective cross-examination more difficult” (pp. 232-233). “The inaccuracies the process introduces can be reduced, althhough perhaps not eliminated, by the use of procedural safeguards” (p. 233). “The more traditional means of assessing accuracy of testimony also remain applicable in the case of a previuosly hypnotized defendant. Certain information recalled as a result of hypnosis may be verified as highly accurate by corroborating evidence. Cross-examination, even in the face of a confident defendant, is an effective tool for revealing inconsistencies” (p. 234). “We are not now prepared to endorse without qualifications the use of hypnosis as an investigative tool; scientific understanding of the phenomenon and of the means to control the effects of hypnosis is still in its infancy. Arkansas, however, has not justified the exclusion of all of a defendant’s testimony that the defendant is unable to prove to be the product of prehypnosis memory. A State’s legitimate interest in barring unreliable evidence does not extend to per se exclusions that may be reliable in an individual case. Wholesale inadmissibility of a defendant’s testimony is an arbitrary restriction on the right to testify in the absence of clear evidence by the State repudiating the validity of all posthypnosis recollections” (p. 234).

Udolf, R. (1990). Rock v. Arkansas: A critique. International Journal of Clinical and Experimental Hypnosis, 38 (4), 239-249.

Rock v. Arkansas is the first United States Supreme Court decision that addresses the conflict between a criminal defendant’s right to testify in his or her own behalf and a state’s right to impose a restrictive rule of evidence barring hypnotically refreshed testimony. The present critique describes the operative facts in Rock v. Arkansas and the majority and minority decisions. It also highlights some of the psychological and legal issues involved and speculates on what Rock v. Arkansas may portend for the broader issue of the admissibility of hypnotically refreshed testimony in general.

Pinizzotto, Anthony J. (1989). Memory and hypnosis: Implications for the use of forensic hypnosis. Professional Psychology: Research and Practice, 20 (5), 322-328.

The author reviews arguments regarding hypnosis in forensic investigations, offers procedures of a nonhypnotic nature to enhance memory recall, and suggests guidelines for hypnosis in criminal cases. The effects of hypnosis on memory, as well as the concomitant dangers regarding those effects, are discussed.

Sanders, Glenn S.; Gansler, David A.; Reisman, Stephen Jr. (1989). The effects of hypnosis on eyewitness testimony and reactions to cross-examination. American Journal of Forensic Psychology, 7, 33-60.
Investigative hypnosis has been a widely used and valuable police technique, but recent court rulings have expressed reservations about the admissibility of hypnotically related testimony. The proposed research is the first directly relevant evaluation of the most serious of the courts’ reservations: the allegation that hypnosis produces excessive and unshakable levels of confidence in witnesses, thereby effectively denying opposing counsel the right of cross-examination. Volunteers from the community witnessed a simulated crime, and were then interviewed by a professional police investigator to obtain evidence and testimony. Two-thirds of these witnesses were randomly assigned to have their memory refreshed by one of two hypnotic induction techniques. All witnesses were subsequently examined and cross-examined by a pair of practicing criminal lawyers, and their videotaped testimony was evaluated by another volunteer sample of community residents serving as jurors. On both objective and subjective measures, hypnotized witnesses provided more complete and internally consistent testimony. However, neither form of hypnotic induction led to greater witness confidence, credibility, or resistance to cross-examination. Our results generally replicate previous findings in a more realistic investigative simulation. The discussion considers artifactual explanations of the confidence null effects, and explores theoretical and policy implications of the data.

People responding to a newspaper ad asking for volunteers who would be paid for participating in psychology research at the State University were later asked to undergo hypnosis. Of 45 who responded to the ad, six (13%) declined to have hypnosis. This rate of refusal has relevance to research on clinical hypnosis that requires paid volunteer participants.

Waxman, David (1989). Nothing but the truth? Commentary on the 1988 Home Office Circular No. 66. [Comment/Discussion] .

The Commentator agrees with views expressed in the Home Office Circular and suggests that if hypnosis is used in an investigation, the following guidelines should be observed.
” 1. The subject must be entirely willing to undergo hypnosis. Signed and witnessed consent should be obtained.
2. No accused person or suspect should be hypnotized in an attempt to obtain information.
3. Immunity from prosecution should never be offered to the person being hypnotized.
4. Hypnosis should be carried out by a physician or psychologist with knowledge in this field, experience in its clinical use and special training in the use of forensic hypnosis.
5. The hypnotist must be an independent specialist, with no responsibility either to the prosecution or the defence.
6. His opinion must be entirely unbiased. Therefore he should only be given some basic and known facts of the case. He should have no knowledge of the suspect so that he may remain impartial.
7. A full medical and psychiatric evaluation of the subject must be made by the specialist before commencing hypnosis. He must be satisfied that the subject is a fit person to undergo hypnosis.
8. Tape recordings and video-tape recordings covering the entire area of the room in which the hypnosis is to take place should be made. The subject should be informed that the interview is being recorded. The tapes should be opened as the subject enters the room by the police officer in charge of the case, with venue, date and time duly stated and sealed again after all discussion is concluded.
9. Only the specialist and the subject should be in the interview room during the examinatino in order to avoid inadvertent cueing of the latter by other persons.
10. There should be no prompting or cueing of the subject at any time during the interview.
11. The subject’s general practitioner should be informed of the interview having taken place if considered advisable by the specialist. The latter should be available to undertake follow-up if required.
12. Information obtained under hypnosis should not be regarded as irrefutable evidence in a court of law. Corroborative evidence should always be obtained by the police. The corollary is that information obtained at the interview cannot be used to corroborate other information for which there is no evidence” (pp. 45-46).

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 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.

Perry, Campbell (1988, November). An interactionist position on hypnosis. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Asheville, NC.

Context makes differential contributions across items on scales, e.g. amnesia depends mostly on individual differences. Yet in the 19th Century it occurred almost inevitably, spontaneously, because of expectancy of therapist and patient.
Success in pain reduction is much greater in clinic (Crasilneck; Melzack et al; Cedercrentz – skull injury) than in lab (Hilgard’s studies of highs and lows).
Central to the disagreement about special state/socio-behavioral theories is the question, “What are the origins of beliefs about hypnosis?” The beliefs can be modified by experience, which is mediated by individual differences.
Author suggests trying to predict which individual will respond to which hypnosis item. Since there are at least 3 factors in hypnotizability scales, one needs a number of variables to do this type of research. Nadon et al (Journal of Personality and Social Psychology 1987) predicted hypnotizability with PICS (an imagery control test) and Absorption scale plus Evans’ Sleep Questionnaire subscale plus Belief in [paranormal events] subscale: predictions were 63% correct. PICS (as compared with other imagery tests) reflects imagery as a _preferred mode_ of thinking. Now, can we predict who will make highly confident errors when asked to remember details of a crime? Who is more vulnerable when told a pseudomemory is veridical?
In a test of this question, mimicking a field setting, the authors weren’t able to predict the people who would make errors, who functioned at the same level following neutral instructions (“We don’t know what we’ll find”) and Reiser-type instructions (“You can use a zoom lens to see the scene up close”) in hypnosis. Also, the effect of an increase in confident errors was greater for highs than for lows. People with high hypnotizability and low PICS made the most errors. N.B. Since lows also increased in errors, one should be cautious in any case.
Creation of pseudomemory research: Using SHSS:C and PICS one can predict 81% of those who accepted and reported the implanted pseudomemory.

Pettinati, Helen M. (1988). Hypnosis and memory. New York and London: Guilford Press.

From a review in British Journal of Experimental and Clinical Hypnosis, 7, 175- 178, by Vernon H. Gregg]:
Book has 5 sections: 1. method, theory 2. mechanisms of memory enhancement 3. hypnotic and other forms of reversible amnesia 4. clinical uses of hypnosis for increasing accessibility of memories and fantasies 5. Summary
The chapter by Martin Orne et al presents a comprehensive review. Perry, Lawrence, d’Eon and Tallant contribute a lively assessment of age regression procedures in the elicitation of inaccessible memories. They provide a description of procedures, a brief historical review, and discuss problems of confabulation and creation of pseudomemories. Their account is illustrated by clinical and forensic examples and gives an interesting account of belief in reincarnation in terms of source amnesia.
Section 3 has Hollander’s chapter on hysteria and memory, which illustrates the concept of reversibility of amnesia with two types of hysterical conditions: one of these types, the dissociative disorders, has the potential for amnesia to be reversed but the other, histrionic personality disorders, is characterized by no reversibility.
In the section on clinical studies of memory enhancement Frankel and Kolb both accept that uncovering repressed memories and fantasies is therapeutically beneficial and that the faithfulness of recovered memories is often not important for therapeutic success. Frankel illustrates the usefulness of hypnosis with several case studies. But he thinks that clinical issues are dealt with too briefly in this book. In her summary chapter Pettinati points to the dearth of systematic research into the effectiveness of hypnosis in clinical settings.

Sheehan, Peter W. (1988). Memory distortion in hypnosis. International Journal of Clinical and Experimental Hypnosis, 36, 296-311.

This paper presents data from a programmatic series of studies that varied the range of conditions affecting potential increase of recall, memory distortions, and distortions of confidence during and following hypnosis. All the studies used a paradigm that exposed Ss to misleading information some time before memory was tested and applied procedures in the hypnotic setting to analyze memory performance in both recognition and free recall. Results from the program failed to demonstrate any increment in accurate memory due to hypnosis, and the accuracy of memory reports in hypnosis was at times significantly reduced. Further, hypnotic recall was distinctively distorted when false information was introduced after, rather than before hypnosis. Results were discussed in relation to the role hypnotic as opposed to contextual variables may play in explaining Ss’ memory test performances, and some legal implications are drawn from the data.

This article investigates 3 major questions: 1. whether hypnosis makes recollections more susceptible to error 2. whether hypnosis reliably enhances recall 3. whether hypnosis alters certitude of what is remembered, independent of accuracy
The author reviews earlier literature, noting that different methodologies lead to different, sometimes conflicting, results. He uses Loftus’ methods, which “allows for systematic exposure to specific information that is erroneous and examines the after- effects of that exposure on subsequent attempts to remember” (p. 298). The Ss are tested initially for memory of an incident, with subtle introduction of false information; then retested in way that probes for correct recall/recognition by presenting the incorrect information as an alternative for response. (Loftus has presented the position that misinformation is incorporated into waking memory, and this examines whether the addition of hypnosis–especially with Ss who are highly hypnotizable–increases the effects.)
Sheehan reports six studies that varied type of memory test (free recall, recognition); type of instruction (hypnotic, waking, simulating); and level of hypnotizability (high, low). Each study dealt with the same incident that depicted an apparent robbery and three false pieces of information about the incident were presented to Ss in the misleading condition. The studies have been published elsewhere as: –Study 1 Sheehan & Tilden, 1983: High and low hypnotizable Ss tested under hypnosis & waking conditions. False information is given before hypnosis. –Study 2 Sheehan & Tilden, 1984: Real & simulating Ss presented with false information prior to hypnotic induction. –Study 3 Sheehan & Tilden, 1986: High hypnotizable and motivated low hypnotizable Ss presented with false information prior to hypnosis. –Study 4 Sheehan, Grigg, & McCann, 1984: Real & simulating Ss presented with false information after hypnotic induction. –Study 5 Sheehan & Grigg, 1985: High hypnotizable and motivated low hypnotizable Ss presented with false information after hypnotic induction –Study 6 (this article reports): High and low hypnotizable Ss tested under hypnosis and waking conditions. False information is given after hypnosis. Scene shown is described by hypnotist in a congruent (robbery) or incongruent (friendly encounter) way
Ss tended to give incorrect responses along the lines of the false cues, but this effect was not greater when hypnosis occurred after the leading information had been given. In two experiments (#4 and #5) the effect was associated with hypnosis. Thus, when Ss are hypnotized they are more likely to be misled by false information. Study 6 did not demonstrate the incorporation of false information into memory, possibly because there was a longer delay between presentation of the information and the memory test itself. This weakening effect of delay has also been shown by Loftus et al. (1978). High hypnotizable Ss in the hypnosis condition showed more distortion than lows not hypnotized in 4 of the 6 studies evidencing distortion.
The authors note that “confidence may be maintained in the hypnosis setting despite the presence of substantial inaccuracy. … Simulating Ss performed just as confidently as real Ss … raising the question that context may determine the results for confidence among real Ss. … Where expectations were out of phase with stimulus events [Study 6], confidence effects involving hypnosis did not emerge” (pp. 304-305).
“Overall, data indicated that hypnotic instruction may be more reliably associated with confidence than level of hypnotizability, though both variables are associated with confidence at one time or another. What is not clear, however, is whether hypnosis itself is at issue or the context of which hypnosis forms a part. That context, of course, may include the belief of Ss brought to the formal test situation that hypnosis increases memory. … Simulating Ss reported higher confidence levels than real Ss when results were analyzed just for the hypnotic setting …, for recognition testing in Study 4; simulating Ss were not distinct from hypnotic Ss under waking conditions of testing. It seems that the hypnotic setting itself, or expectations about it, obviously communicated that an expression of strong conviction was required. Collectively, results demonstrated that simulating Ss believed that a hypnotized person would be more confident, and they therefore reported greater confidence levels during their act of pretense” (pp. 305-306).
In their discussion, the authors note that there was more evidence for mis- reporting than for accuracy, but that hypnosis did not produce more error unless false information was given during hypnosis. High hypnotizable Ss produce many errors with a high level of confidence, but since simulators feign hypnosis by reporting high levels of confidence, it may be expectations about the ability of hypnosis to improve recall that influences these results. “Such expectations may influence hypnotic recall for all Ss, but this would not explain differential levels of confidence between high and low hypnotizable Ss when both are tested in exactly the same way–that is, when task demands are held constant” (p. 306).
“One major implication of the data is that future research should move away from focusing only on the truth validation or distorting influence of hypnosis to emphasize the role contextual features may play in accentuating memory distortion effects” (p. 307). “The one clear finding across all of the studies in the program was that hypnosis does not increase memory, and the findings provide no basis to justify the forensic application of hypnosis given that the point of forensic application is that hypnosis will help memory. Data also indicate that when leading questions are asked under hypnosis, they are likely to be more effective in distorting memory reports than when such questions are asked without hypnosis. Low resistance to misinformation was present among both hypnotic and waking Ss, but separated the two groups when the false information was given in hypnosis.
“One of the major inferences … is that the most substantial risk to using hypnosis may lie not only with the tendency to mis-report itself, but with the tendency for hypnotic Ss to be convinced in their reporting no matter what the accuracy of their statements. This effect was pervasive enough that it may offer sufficient grounds for restricting how hypnosis should be used forensically” (p. 308).

Whitehouse, Wayne G.; Dinges, David F.; Orne, Emily C.; Orne, Martin T. (1988). Hypnotic hypermnesia: Enhanced memory accessibility or report bias?. Journal of Abnormal Psychology, 289-295.

Laboratory studies of hypnotic hypermnesia have yielded inconsistent evidence of memory enhancement, and the process responsible for the occasional positive findings have eluded identification. The present experiment assessed delay recall for filmed material under conditions in which subjects were required to answer all questions, by guessing if necessary. They also rated confidence in the accuracy of each response. After an initial wake-baseline forced-recall test, subjects were randomly assigned to hypnosis or waking conditions for a second forced-recall test. Both groups of subjects recalled additional correct details on the second test, but the magnitude of this hypermnesia was no greater for subjects exposed to the hypnosis treatment. Hypnotized subjects did, however, exhibit a significantly greater increase in confidence for responses designated as “guesses” on the prior waking test–a finding consistent with the view that hypnosis engenders a shift in the subjective criterion for what constitutes a “memory”. Implications of these findings for the use of hypnosis in forensic situations are discussed.McCann, Terry; Sheehan, Peter W. (1987, October). Pseudomemory creation and confidence in the experimental hypnosis context. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Los Angeles.
After watching a video-tape of a bank robbery incident, 34 out of 40 highly hypnotizable subjects displayed pseudomemory reports subsequent to the administration of false memory suggestions given after hypnotic induction instructions. Incorporation of elements of pseudomemory into recall reports was accompanied by increased confidence ratings, but confidence ratings for those subjects displaying most pseudomemory distortion at recall fell appreciably when subjects were confronted with the reality constraints associated with recognition testing. Data imply that pseudomemories associated with hypnotic suggestion are not always accompanied by increased conviction or certitude, nor are they resistant to change in the face of contrary evidence. Data further indicate that subjects adapt both accuracy and confidence responses to the stimulus conditions of testing, implying that accuracy and confidence ratings may covary meaningfully.

Register, Patricia A.; Kihlstrom, John F. (1987). Hypnotic effects on hypermnesia. International Journal of Clinical and Experimental Hypnosis, 35, 155-170.
The effects of hypnotic suggestions for improved memory were explored using procedures known to produce hypermnesia in the normal waking state. In Experience 1, 64 trait adjectives were randomly assigned to orthographic, phonemic, semantic, and self-referent orienting tasks in an incidental learning paradigm. These were presented to 40 Ss classified as low, medium, high, or very high in hypnotizability, followed by a series of 3 recall trials: immediately after the study phase, following a hypnotic suggestion for enhanced memory, and after termination of hypnosis. There were significant effects of both encoding condition and repeated trials on incidental recall. However, the hypermnesia effect observed in other experiments was not obtained, and there were no memory effects attributable to hypnosis. In Experiment 2, 60 line drawings of common objects were presented to an overlapping sample of 40 Ss, followed by the same recall procedure employed in Experiment 1. There was a significant hypermnesia effect of repeated trials, but again no effects attributable to hypnosis. In Experiment 1, the hypnotic procedure seemed to interfere with the normal waking hypermnesia effect; in Experience 2, hypnosis failed to enhance it. These results fail to support the use of hypnosis to enhance the memories of eyewitnesses in forensic investigations.

The designs for Experiments 1 and 2 are complex and detailed, so they are not summarized here. The DISCUSSION follows, however:
“The present study concerned the effect of hypnotic suggestions on hypermnesia for words presented under conditions of incidental learning (Experiment 1) and for pictures studied under conditions of intentional learning (Experiment 2). Experiment 1 failed to produce a hypermnesia effect; in fact, recall _decreased_ on the second trial, after hypnosis was induced, though these memories were recovered on a subsequent waking recall trial (for contrary findings, see Shields & Knox, 1986). This loss of memory was not a specific effect of hypnosis, because the extent of loss was not associated with S’s hypnotizability. Experiment 2 succeeded in producing hypermnesia, but the effect was not a function of hypnotizability. These findings are consistent with those of Nogrady et al. (1985). Apparently hypnosis does not enhance waking hypermnesia effects.
“Dywan and Bowers (1983), who also embedded hypnosis in the waking hypermnesia paradigm, obtained somewhat different results. They observed a significant improvement in memory in hypnosis over and above what had been produced by waking hypermnesia. Moreover, they observed a significant increase in false recall on the hypnotic trial. These differences may have been due to the instructions given to Ss. Following the forced-recall procedure employed by Erdelyi and Becker (1974), Dywan and Bowers (1983) required their Ss to produce 60 items (the number of stimuli that had been presented during the study phase), even if they had to guess or respond randomly in order to do so. By contrast, neither Experiment 2 nor that of Nogrady et al. (1985) employed this forced-recall procedure. In addition, the instructions in Experiment 2 stressed accuracy in recall.
“The implication of these three studies taken together is that there is a high correlation between two products of hypnotic hypermnesia: any increase in accurate recall resulting form hypnotic procedures may be offset by a corresponding increase in false recollections. When Ss are not urged to produce more or new memories, hypnosis may not increase false recollection, but it will not increase accurate recall either. When hypnotized Ss are strongly encouraged to guess, as in Dywan and Bowers (1983), or in forensic situations, they may improve their levels of accurate recall, but this will be at the price of an increase in false recall. In fact, a study of normal waking memory by Roediger and Payne (1985) found that forced-recall instructions–in which Ss were asked to guess after they had exhausted their confident recall-increased intrusions tenfold over a condition in which Ss were warned ‘not to guess wildly [p. 4]’–although there were no differences in correct recall. Although Roediger and Payne did not collect confidence ratings, we can assume that their Ss were able to distinguish between wild guesses and accurate memories (Johnson, 1985). Hypnotized Ss, however, appear to be poor at making this distinction (Dywan & Bowers, 1983; Nogrady et al., 1985).
“In the final analysis, hypnosis may encourage Ss to guess, but it does not appear to improve memory per se. Interestingly, hypnotized Ss do not seem to realize that they are guessing. Overall, their confidence levels tend to increase with no corresponding increase in accuracy (Dywan & Bowers, 1983; Nogrady et al., 1985). These Ss appear to confuse memories of prior guesses with those of the actual experience. For this reason, although cautionary instructions are likely to yield nothing new, instructions to guess are much more likely to produce misleading results when given to hypnotized individuals. This suggests that hypnosis is an unreliable technique for enhancing memory, and it should be used in forensic and other applied settings only with the utmost caution (for some guidelines see American Medical Association, 1985,; M. T. Orne, 1979; M. T. Orne, Soskis, Dinges, & E. C. Orne, 1984). Other psychological techniques for improving memory may not possess these liabilities, and they may prove more suitable for use in field settings (Geiselman et al., 1985).”

Nash, Michael R.; Drake, Stephen D.; Wiley, Stephen; Khalsa, Sahib; Lynn, Steven Jay (1986). Accuracy of recall by hypnotized age regressed subjects. Journal of Abnormal Psychology, 95 (3), 298-300.

Investigated the accuracy of the factual recall of highly hypnotically susceptible undergraduates both during and after the hypnotic procedure. Third-party verification (parent report) of the accuracy of recall was obtained for 2 S groups: 14 hypnotized Ss and 10 postsimulation control Ss. Results indicate that, despite the similarity to children in their way of relating to transitional objects, hypnotic Ss were significantly less able than control Ss to correctly identify the specific transitional objects actually used. Furthermore, all recollections obtained during hypnosis were incorporated into posthypnotic recollections, regardless of accuracy. Clinical implications are discussed.

Sheehan, Peter W.; Tilden, Jan (1986). The consistency of occurrences of memory distortion following hypnotic induction. International Journal of Clinical and Experimental Hypnosis, 34, 122-137.

The present study examined a range of circumstances for their effects on the vulnerability of hypnotic Ss to memory distortion. 26 high and 26 low hypnotizable Ss were tested individually in a design in which Ss received information that was either misleading or not misleading about a series of events depicting an apparent robbery. The information was presented prior to Ss being given hypnotic instructions, and low hypnotizability Ss were especially motivated for positive response in the session. Memory for the robbery was studied across a range of measures that included forced choice recognition, free recall, and response to leading questions. Results demonstrated predictably variable effects. The 2 groups performed appreciably differently in free recall, for example, while in recognition testing, data indicated that high and low hypnotizable Ss both incorporated misleading information into their memories to the same degree. Some implications of the data for the forensic context are discussed.

56 Ss were prescreened with Harvard Group Scale of Hypnotic Susceptibility, Form A, defining highs = 9-12, lows = 0-3. Used Loftus materials for testing memory (wallet snatching sequence, on a series of slides). Errors were classified as errors of fact, of inference, or conjectures. Highs had more intrusions that were errors of fact than lows did (p<.05), confirming the earlier results published by Sheehan & Tilden, 1984. There was no significant association between hypnotizability level and intrusion of central detail (description of robber and victim), but 57% of highs and only 18% of lows intruded peripheral objects incorrectly into their own narrative reports (i.e. descriptions given of the surroundings), p<.01. There were trends for high hypnotizable Ss to recall more objects correctly than low hypnotizable Ss during narrative reporting (p<.06) and to recall more central objects (p<.06), but not more peripheral objects. There may have been a loosening of criteria for memory among high hypnotizables, because they appeared to produce both greater accuracy and inaccuracy in recall of certain types of detail. During the recognition testing, high hypnotizables exhibited significantly greater confidence in their responses than low hypnotizable Ss, but there was no group difference for accuracy. "Results for both tests of integration then (recognition and free recall) confirmed the prediction that hypnotic Ss incorporate false information into their memory, and the effect did not differentiate high from low hypnotizable Ss" (p. 131). When a leading question implied that traffic lights were present in the scene, 34% responded in some way to that suggestion, and 20% said that they could see the lights in their minds eye; but 14% said that "although they could not see the lights, they nevertheless remembered they were there" (p. 132). Response to the leading question did not differ between high and low hypnotizable Ss. In their discussion, the authors note that hypnosis did not enhance memory in this study. "Results overall suggest that hypnotic induction lowers the correspondence between confidence and accuracy. In the present study, hypnotic Ss were confident about their recall when the degree of accuracy of their reports suggested they should have been quite uncertain. Hypnotic instruction itself would appear, then, to establish conditions that spuriously facilitate a high degree of confidence in the reports that Ss produce. "A major point to be made about the present study is that both general distortion and confidence effects observed here cannot necessarily be attributed to hypnosis. There was no independent comparison condition, for example, to contrast results for hypnotic Ss with results for Ss receiving no induction procedures. Effects, then, could be attributed to the hypnotic context as much as to the effects of induction per se, and context rather than state may be responsible for the vulnerability of hypnotic Ss that has been observed. The influence of context is seen at least in the clear evidence for an interaction between situational factors and hypnotizability. In free recall, hypnotizable Ss were more prone to distortions than unhypnotizable Ss, while in recognition, hypnotizable and unhypnotizable Ss were equally prone. Mode of testing is, therefore, a major contextual variable that is related to the nature of the distortion and confidence effects that can be observed. Present data further indicate that the hypnotic context is associated with memory distortion even in Ss who have little capacity for being hypnotized, but who are instructed to believe that they can, in fact, experience much of what is being suggested" (pp. 133-134). Forensic implications need to be tempered because of difference between laboratory and real life, but practitioners nevertheless should be cautious. "While it is not true that hypnotized persons, by virtue of their hypnotizability level, will always distort their reports more obviously than nonhypnotic Ss, so as to bring their recollections into line with what is implied or suspected, parameters do exist that clearly increase the risks of distortion that can occur after hypnotic instruction. This is evidenced, for example, by the distinctive distortion effects that have been demonstrated for high hypnotizable Ss when they are given induction instructions and later requested to tell their story in their own way. Overall, the present data imply that the law needs to closely evaluate the impact of the different settings in which hypnosis takes place and the different ways in which misleading information can be communicated to persons who are later asked to testify. The potential risks of hypnosis--as well as its utility--will depend critically on how that information has been conveyed, and the way in which Ss' memories are tested" (pp. 134- 135). Wilson, L.; Greene, E.; Loftus, Elizabeth F. (1986). Beliefs about forensic hypnosis. International Journal of Clinical and Experimental Hypnosis, 34 (2), 110-121. The beliefs people hold about hypnosis have an impact on the behavior of a witness who is hypnotized and on juries who hear these witnesses and weigh hypnotically influenced testimony. Students in Experiment 1 and registered voters from the community in Experiment 2 responded to questions about forensic hypnosis. Over 70% of the students as compared to about 50% of the community members were favorable toward the use of hypnosis by police for memory enhancement. In both groups, however, twice as many people reported that they would put less faith rather than more faith in the testimony of someone who had been hypnotized. A substantial portion of the students affirmed common myths about the effects of hypnosis on memory and behavior. 1985 Orne, Martin T. (1985). The use and misuse of hypnosis in court. In Rosner, Richard (Ed.), Critical issues in American psychiatry and the law (2, ). New York: Plenum Press. (Reprinted from Crime and Justice: An Annual Review of Research, vol. 3, edited by Michael Tonry and Norval Morris, 1981, The University of Chicago Press.) NOTE An earlier version of this essay appeared in the Monograph Issue of the International Journal of Clinical and Experimental Hypnosis on the forensic uses of hypnosis, 27 (4) (1979): 311-41. Stager, Gordon L.; Lundy, Richard M. (1985). Hypnosis and the learning and recall of visually presented material. International Journal of Clinical and Experimental Hypnosis, 33, 27-39. To examine the effect of hypnosis on the learning and recall of visually presented material, high and low hypnotizable Ss were presented, under hypnotized or awake conditions, with a short, entertaining movie followed by questions about the movie. 2 week later Ss, hypnotized or awake, were again asked questions concerning the movie. The principal finding was that high hypnotizable Ss in the hypnotic induction condition increased accurate recall without increasing inaccurate recall. Neither hypnotizability nor hypnotic induction at learning affected recall. The major finding of the present study is that hypnosis during recall of previously learned material is facilitative, but that hypnosis during that previous learning is not. Thornton, P. (1985). Use of hypnosis by the police in the investigation of crime. Which way should the pendulum swing?. British Journal of Experimental and Clinical Hypnosis, 2 (2), 125-127. (National Council for Civil Liberties' opinion about the Home Office's proposed guidelines on use of hypnosis by the police in the investigation of crime) NOTES "Conclusions 20. The dangers of using hypnosis in the criminal process are clearly demonstrated from a civil liberty point of view. 21. Inaccurate and misleading information supplied under hypnosis could lead to the investigation and arrest of innocent parties. 22. A witness who had undergone hypnosis could innocently yet confidently give false evidence. 23. Magistrates or juries may tend to rely on answers given under hypnosis as being more reliable than those given in the waking state simply because of the mystery surrounding the process. 24. A witness could be unfairly yet effectively cross-examined on the video-recording of the hypnotic state. 25. Hypnosis should not be used even as a last resort in the investigation of crime" (p. 127). 1984 Orne, Martin T.; Dinges, David F.; Orne, Emily Carota (1984). On the differential diagnosis of multiple personality in the forensic context. International Journal of Clinical and Experimental Hypnosis, 32 (2), 118-169. The problems of diagnosing multiple personality disorder in a forensic context are discussed, and illustrated by the case of State v. Kenneth Bianchi (1979), a defendant who was both charged with first degree murder and suspected of having the disorder. Because of the secondary gain (e.g., avoiding the death penalty) associated with the diagnosis of multiplicity in such a case, hypotheses had to be developed to permit an informed differential diagnosis beween multiple personality and malingering. If a true multiple personality disorder existed, then (a) the structure and content of the various personalities should have been consistent over time, (b) the boundaries between different personalities should have been stable and not readily altered by social cues, (c) the response to hypnosis should have been similar to that of other deeply hypnotized subjects, and (d) those who had known him over a period of years should have been able to provide examples of sudden, inexplicable changes in behavior and identity, and evidence to be the case. Rather, the content, boundaries, and number of personalities changed in response to cues about how to make the condition more believable, and his response to hypnosis appeared to reflect conscious role playing. Further, the life history indicated a persistent pattern of conning and deliberate deception. It is concluded that Mr. Bianchi was simulating a multiple personality and the diagnosis of Antisocial Personailty Disorder with Sexual Sadism was made. Differential diagnoses and the clinical aspects that appeared to account for his behavior are discussed. Sheehan, Peter W.; Tilden, Jan (1984). Real and simulated occurrences of memory distortion in hypnosis. Journal of Abnormal Psychology, 93 (1), 47-57. 79 undergraduates were prescreened for high or low susceptibility to hypnosis (Harvard Group Scale of Hypnotic Susceptibility--Form A) and tested individually to examine memory distortion in hypnosis. Independent groups of Ss were allocated to a 2 x 2 factorial design in which s grouping (hypnotic or simulating) was crossed with an information condition that either misled or did not mislead Ss about a series of scenes depicting an apparent robbery. It was hypothesized that memory distortion would characterize the performance of hypnotic Ss when memory was examined in unstructured, narrative recall. Results show that real Ss were differentiated appreciably from simulating Ss in the extent to which they incorrectly intruded uncued errors (i.e., errors not arising from misleading information) into their memories but not in their intrusion of cued errors (i.e., errors arising from misleading information). Real Ss remembered correctly more detail of a peripheral kind but also distorted more with respect to the same kind of detail. Results overall negate the view that earlier memory traces are revived in hypnosis, thereby leading to more accurate retrieval, and suggest that hypnotic Ss bring distinctive styles of information processing to bear on their recollections of complex, socially meaningful events Sheehan, Peter W.; Grigg, Lyn; McCann, Terry (1984). Memory distortion following exposure to false information in hypnosis. Journal of Abnormal Psychology, 93 (3), 259-265. 92 Ss preselected for hypnotic responsiveness on the Harvard Group Scale of Hypnotic Susceptibility--Form A were tested in strict application of the real-simulating model of hypnosis to examine the hypothesis that hypnotic Ss distinctively incorporate false material into their memories when that material is introduced after, rather than before, hypnotic induction. Both real (n = 46) and simulating (n = 46) Ss were either exposed or not exposed to misleading information after receiving induction instruction. Procedures for testing were otherwise identical to those adopted in an earlier study by the 1st author and J. Tilden (see PA, vol 71:14147) in which false information was presented prior to hypnosis. Results confirm the hypothesis and show that hypnotic Ss differed appreciably from simulating Ss by incorporating more misleading material into their memory. Findings highlight the possibility of distinctive processing in hypnosis and implicate lowered critical assessment by hypnotic Ss of information they confidently accepted in the hypnotic context (20 ref) Flatt, Jennifer R. (1983). What makes therapy work? Thoughts provoked by a case study. Australian Journal of Clinical and Experimental Hypnosis, 11 (2), 63-72. The case described is offered as illustrating the doubt common to introspective therapists: what _did_ cure the patient? "Francesca's" presenting problem and the object of the short-term psychological intervention described here, was a fairly circumscribed set of fears related to enclosed spaces. The therapeutic approach adopted was primarily hypnobehavioural, with hypnotically-assisted systematic desensitization and "in vivo" exposure being the main components of the planned programme. However, at the client's suggestion, one hypnotic session with content planned by the therapist as age regression produced rather dramatic and unexpected results claimed by the patient to effect complete cure. NOTES The therapist suggested that "her mind would take her back to a time that was important in understanding her fears and that she would be able to stay calm and relaxed while this past event was revealed to her" (p. 69. She subsequently imagined being in a cave, peaceful and calm. "On being roused from hypnosis, Francesca eagerly described her cave image. She was enthusiastic about the significance of this experience, claiming that it was evidence that in a _previous life_ she had died from being locked into a cave as some sort of punishment and that this pexperience made her fear of enclosed places rational and comprehensible to her" (p. 69). Karlin, Robert (1983). Forensic hypnosis--two case reports: A brief communication. International Journal of Clinical and Experimental Hypnosis, 31 (4), 227-234. Two criminal cases are briefly described. In these cases, hypnosis was used to "refresh the recollection" of the victim. In each case, the victim's unsupported identification of a perpetrator, produced through hypnosis, was the sole evidentiary basis of the prosecution. There was considerable evidence that both identifications were based on confabulation. 1981 Zelig, Mark; Beidleman, William B. (1981). The investigative use of hypnosis: A word of caution. International Journal of Clinical and Experimental Hypnosis, 29 (4), 401-412. The purpose of the present experiment was to determine the efficacy of hypnosis for enhancing the recall of Ss exposed to a stress provoking motion picture. This stimulus, which vividly displayed several workshop accidents, was selected to provide an analog to witnessing an actual crime. After viewing the film, Ss were questioned in either hypnosis or in a waking state and responded to a questionnaire which contained leading and nonleading questions. Dependent measures included the number correct, number of errors, and the average confidence rating given to their responses. Analyses of these data revealed that waking Ss were significantly more accurate on leading questions. No significant differences were observed when Ss' responses to nonleading questions were examined. Post hoc correlational analyses across both hypnotic and waking conditions revealed that hypnotic susceptibility and confidence ratings were positively correlated while susceptibility and the number of correct responses were not significantly correlated. These findings are compared with previous research and the resulting implications for hypnoticalloy conducted interrogations are discussed. 1979 Ault, R. L. Jr. (1979). FBI guidelines for use of hypnosis. International Journal of Clinical and Experimental Hypnosis, 27 (4), 449-451. The Federal Bureau of Investigation uses hypnosis as a tool for investigative purposes in selected cases where further leads are needed and witnesses or victims are willing to participate in a hypnotic interview. All sessions are tape recorded, preferably by video. A hypnotic interview cannot necessarily provide accurate leads, and therefore careful investigative work is done to verify the accuracy of any information obtained in hypnosis. Psychiatrists, psychologists, or physicians specially trained in hypnotic techniques have been employed to add protection for the witnesses or victims being questioned under hypnosis. Hilgard, Ernest R.; Loftus, Elizabeth F. (1979). Effective interrogation of the eyewitness. International Journal of Clinical and Experimental Hypnosis, 27 (4), 342-357. Eyewitness reports have been investigated in the psychological laboratoy from time to time ever since 1900. Specimen studies from the early period and from the last decade indicate that free reports are consistently more accurate but less complete than reports obtained through specifically directed inquiry. The optimal combination is free report followed by the asking of specific questions. The wording of those questions, however, can have a substantial effect on the answers given. Furthermore, the wording of questions put to a witness can distort the witness's memory for the previously experienced event. These techniques and findings have implications for the study of other "retrieval" techniques such as hypnosis. Although laboratory-type control cannot be expected in practical settings, scientific validation of interrogation methods as practiced can be obtained if recording is complete and accurate, if proccesses of memory restoration or amplification are studied as they occur in the course of interrogation, and if outcome studies are fully reported, including both successes and failures to gain new information or to substantiate existing information. Orne, Martin T. (1979). The use and misuse of hypnosis in court. International Journal of Clinical and Experimental Hypnosis, 27, 311-341. The various forensic contexts in which hypnosis has been used are reviewed, emphasizing its advantages and pitfalls. The technique may be helpful in the context of criminal investigation and under circumstances involving functional memory loss. Hypnosis has no utility to assure the truthfulness of statements since, particularly in a forensic context, subjects may simulate hypnosis and are able to willfully lie even in deep hypnosis; most troublesome, actual memories cannot be distinguished from confabulations either by the subject or by the hypnotist without full and independent corroboration. While potentially useful to refresh witnesses' and victims' memories to facilitate eyewitness identification, the procedure is relatively safe and appropriate only when neither the subject, nor the authorities, nor the hypnotist have any preconceptions about who the criminal might be. If such preconceptions do exist -- either based on information acquired before the hypntotic procedure or on information subtly communicated during the hypnotic procedure -- hypnosis may readily cause the subject to confabulate the person who is suspected into his "hypnotically enhanced memories." These pseudomemoreis, originally developed in hypnosis, may come to be accepted by the subject as his actual recall of the original events; they are then remembered with great subjective certainty and reported with conviction. Such circumstances can create convincing, apparently objective "eyewitnesses" rather than facilitating actual recall. A number of minimal safeguards are proposed to reduce the likelihood of such an eventuality and other serious potential abuses of hypnosis. Putnam, W. H. (1979). Hypnosis and distortions in eyewitness memory. International Journal of Clinical and Experimental Hypnosis, 27 (4), 437-448. An experiment was conducted to determine whether eye-witnesses questioned under hypnosis are more likely to answer leading questions incorrectly than eyewitnesses questioned in a normal waking state. Ss viewed a videotape-recording depicting a car-bicycle accident and were questioned about the details of the accident. Half of Ss were questioned under hypnosis and half of Ss were questioned in a normal waking state and in each of these conditions, half of Ss were questioned 15 minutes after seeing the videotape-recording and half were questioned after a 24-hour delay. The results revealed that Ss in the hypnosis condition made significantly more errors on leading questions (questions that suggested an incorrect answer) than Ss in the normal waking condition. There were no significant differences between the groups of Ss on objective, non-leading questions. The results are discussed in terms of their implications for the use of hypnosis in police investigations.