Temporal organization of recall during posthypnotic amnesia.

Amnesia suggestions were administered to 35 undergraduates of low, medium, and high hypnotic susceptibility (the Stanford Scale of Hypnotic Susceptibility—Form C) who had learned a word list while hypnotized. The method encouraged Ss to organize the words sequentially. Organization of recall was measured on recall trials conducted before, during, and after suggested amnesia. Highly hypnotizable Ss showed a breakdown in temporal organization during amnesia, followed by a recovery of this organization after the suggestion was canceled. Results suggest that posthypnotic amnesia involves a disruption in the contextual relationships among memory items. Findings are discussed in the context of models that construe memory as a network of modes representing concepts and associative links between them. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An event-related potential investigation of posthypnotic recognition amnesia.

Forty-two individuals selected for high hypnotizability or for low hypnotizability were taught lists of words during hypnosis and assessed for recognition following hypnosis using event-related potential (ERP) procedures, both before and after the cue to reverse amnesia. A subgroup of low-hypnotizable participants were asked to simulate hypnotic behavior. All participants had larger late positive component (LPC) amplitudes to learned than to unlearned words, regardless of whether amnesia was reported. The highly hypnotizable participants who reported recognition amnesia, however, had significant changes in attention-related (P1 and N1) and recognition-related (N400 and LPC) ERP component amplitudes as a function of whether amnesia was reported. These data suggest that posthypnotic amnesia may involve alterations in the processes of attention, selection, and accessibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subjective and categorical organization of recall during posthypnotic amnesia.

Conducted 2 experiments to determine the fate of organization of recall during posthypnotic amnesia. In both studies, amnesia suggestions were administered to undergraduate Ss of low, medium, and high hypnotic susceptibility who had learned a word list by the method of free recall while they were hypnotized. In Exp I (n?=?44), words were unrelated to each other, and subjective organization was measured by raw and adjusted pair frequency. In Exp II (n?=–&59), words were drawn from various taxonomic categories, and category clustering was measured by repetition ratio, modified repetition ratio, and adjusted ratio of clustering. Results indicate that, compared to baseline levels, subjective organization and category clustering did not decrease reliably during the time the amnesia suggestion was in effect. Moreover, these aspects of strategic organization were not significantly correlated with the number of items recalled during amnesia. Both findings contrast with previous results concerning temporal organization of a word list memorized by the method of serial learning. Findings suggest that the disruption of retrieval processes in posthypnotic amnesia may be limited to certain organizational schemes. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directed forgetting and posthypnotic amnesia: Information processing and social contexts.

In three experiments we compared posthypnotic amnesia (PHA) with directed forgetting (DF), evaluating subjects' hypnotic susceptibility, hypnotized or not. Experiment 1 suggested that the memory processes in PHA and DF were not the same. Low and high susceptibility subjects responded differently in the two contexts. Experiment 2 demonstrated a context effect for highly susceptible subjects: They showed the usual DF response outside hypnosis but not during hypnosis. Experiment 3 showed that high and low susceptibility subjects responded similarly to DF instructions outside hypnosis, eliminating the susceptibility as an important variable in the DF response. We concluded: (a) The interaction of context and susceptibility was the important determinant of unusual DF responses for high susceptibles, and (b) information processing concepts are too limited to explain PHA and perhaps DF. Theories that include interactions appear necessary for an accurate understanding of hypnotic phenomena and perhaps some phenomena usually focused on by cognitive psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suggestibility during the execution of a posthypnotic suggestion.

Determined whether the execution of a posthypnotic suggestion is accompanied by a transient reinstatement of hypnosis. 11 student volunteers were given a verbal inhibition of their name and address as a test suggestion before, during, and after the execution of each of 4 posthypnotic suggestions differing in level of difficulty and degree of anxiety-producing properties. Each suggestion was either preceded or followed by the administration of the test suggestion under hypnosis. Reinstatement of hypnosis (an increase in susceptibility) occurred during the execution of the posthypnotic suggestions, and at no other time, for only 2 ss. Reinstatement always occurred during the execution of the test suggestion if it was executed under hypnosis before it was given posthypnotically. Anxiety and difficulty were not influencing variables and there were unexpected manifestations of psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Breaching hypnotic amnesia by manipulating expectancy.

Prior to hypnotic induction, subjects selected for high hypnotizability and ability to experience hypnotic amnesia were read one of two expectancy manipulations designed to convince them that deepening of hypnosis either would or would not allow them to breach amnesia. After memorizing a list of six words, subjects heard a hypnotic induction, an amnesia suggestion, a challenge to remember, a trance-deepening procedure, and a second challenge to remember. On the first challenge, subjects in both conditions demonstrated considerable and equivalent degrees of amnesia. Following the trance-deepening procedure, subjects in the amnesia expectancy condition displayed even more amnesia, whereas 80% of the subjects in the memory expectancy condition completely recovered their memory of the word list. These data demonstrate that for most subjects in whom hypnotic amnesia can be elicited, it can be completely breached by manipulating subjects' expectancies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnosis as a retrieval cue in posthypnotic amnesia.

Tested the effectiveness of hypnosis as a retrieval cue in a group of 80 highly hypnotizable college students who demonstrated posthypnotic amnesia on an initial recall test. The 40 Ss who received a reinduction of hypnosis showed a significant improvement in memory on a retest; there was a significant loss of memory on a 3rd test following termination of the 2nd hypnosis and a more substantial recovery on a 4th test following administration of a prearranged reversibility cue. Another 40 Ss, who merely relaxed before the 2nd test, showed a similar improvement in memory on the retest but no subsequent memory loss. The amount of trial-to-trial improvement in memory shown by Ss was unaffected by explicit instructions to maintain amnesia until the reversibility cue had been given. It is concluded that posthypnotic amnesia is not a case of state-dependent retention, nor does hypnosis provide retrieval cues that can lead to the emergence of previously unrecalled memories. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disorganized recall during suggested amnesia: Fact not artifact.

In 3 experiments and a reanalysis of previous data, hypnotic and nonhypnotic Ss learned a 9-item categorized word list and were then given an amnesia suggestion for the list. Clustering of recall was measured on the recall trials immediately before the suggestion, during it, and after it was cancelled. In Exp I with 173 undergraduates, hypnotic Ss showed more amnesia than task-motivated Ss. However, partial nonrecallers in both of these treatments showed disorganized (i.e., less clustered) recall during the suggestion as compared to before it or after cancelling it. Exp II, with 100 university students, disconfirmed the hypothesis that the greater amnesia of hypnotic as compared to task-motivated Ss, was due to high levels of relaxation in the hypnotic Ss. Disorganization was again found in partial nonrecallers. The reanalysis of clustering data from previous experiments with 196 Ss demonstrated that the disorganization effect was not an artifact produced by reduced recall during the suggestion period, and Exp III (with 166 18–42 yr old Ss) indicated that Ss who followed instructions and faked partial amnesia when explicitly asked to do so (simulators) showed no disorganization effect. An inattention–encoding specificity hypothesis was developed to account for these findings. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of simulated hypnotic amnesia.

Highly hypnotizable nonsimulators and high- and low-hypnotizable simulators of hypnosis were administered a hypnotic amnesia suggestion and tested for recall and recognition of a previously learned word list. Simulators exhibited higher levels of recall and recognition amnesia than nonsimulators. Most important, simulators recognized "forgotten" words at lower levels than expected by chance significantly more often than did nonsimulators. Implications for the detection of simulated amnesia in clinical samples are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recovery of memory after posthypnotic amnesia

Notes that documentation of the reversibility of posthypnotic amnesia has been hampered by the correlation of hypnotizability with the initial level of response to amnesia suggestions. 691 college students were placed in groups differing in hypnotic susceptibility that could be matched for initial amnesia recall, thereby eliminating the ceiling effect. At virtually every point along the distribution of initial amnesia response, hypnotizable Ss were significantly better able than insusceptible Ss to recapture the previously blocked memories after the amnesia suggestion was lifted. Conversely, those Ss who showed reversibility of amnesia were more responsive overall to hypnosis than those who did not. It is concluded that reversibility is of value in distinguishing between amnesia and pseudoamnesia and between partial amnesia and nonamnesia. Furthermore, reversibility helps define posthypnotic amnesia as a process involving the disruption of retrieval processes in memory. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posthypnotic amnesia as disrupted retrieval.

Investigated the process of remembering during posthypnotic amnesia by exploring the organization of recalled material in Ss displaying only partial amnesia. During 3 standardized hypnosis scales (Harvard Group Scale of Hypnotic Susceptibility and Forms B and C of the Stanford Hypnotic Susceptibility Scale) suggestions of posthypnotic amnesia were administered to 112 male undergraduates. Hypnotizable Ss tended to recall the scale items in random chronological order, compared to the relatively sequential recall of insusceptible Ss. The difference in temporal sequencing of recall during amnesia indicates that, for the hypnotizable S, posthypnotic amnesia is characterized primarily by a disruption or disorganization of part of the recall process, leaving other aspects of memory processing relatively unimpaired. Results suggest a resolution of the apparent paradox between the subjective reports of amnesic Ss and the objective evidence that the apparently forgotten memories remain available for other cognitive operations. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual forgetting: Posthypnotic source amnesia.

Notes that posthypnotic source amnesia (SA) involves recall of information recently learned during hypnosis without recollection of how the information was acquired. SA occurs when, posthypnotically, an S gives the correct answer to a question like, "An amethyst is a blue or purple gemstone: What color does it become when exposed to heat?" The correct answer seems to pop into the S's mind and he or she does not remember just learning it during hypnosis. SA occurred in 4 of 12 deeply hypnotized totally amnesic Ss but not in 15 unhypnotizable simulating Ss tested by a "blind" experimenter. (Ss were selected by use of the Harvard Group Scale of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scale.) SA also occurred with 31% of 29 deeply hypnotized amnesic Ss in a nonblind experiment. Results show that amnesia cannot be attributed to subtle aspects of the experimental procedure nor to a partial failure of posthypnotic amnesia. SA may provide a model to help understand aspects of several normal and pathological contextual memory disruptions including plagiarism, flashbulb memories, clinical amnesia, the development of phobic states, and other related processes in which there is an apparent dissociation between the content of accessible memories and the context in which the episodic events originally occurred. In SA, Ss know, but do not know how or why they know. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotic amnesia, disorganized recall, and inattention.

High susceptible (Harvard Group Scale of Hypnotic Susceptibility) hypnotic and high and low susceptible nonhypnotic (controls) undergraduates learned a categorized word list to a stringent criterion. The hypnotic Ss were given an amnesia suggestion for the list, and the controls attempted to recall while simultaneously distracting themselves by counting backwards in writing (i.e., dual task). Clustering of recall was measured immediately before, during, and after the suggestion/dual task period. Ss in the 3 treatments who exhibited recall decrements during the suggestion/dual task period showed corresponding and equivalent breakdowns in clustering (i.e., disorganized recall) at this time. Findings are consistent with the hypothesis that the recall deficits and disorganized recall characteristic of hypnotic amnesia result from a failure to attend to the task of target recall during the suggestion period. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repression and hypnotic amnesia.

It was hypothesized that if the process of repression is involved in posthypnotic amnesia, then amnesia should occur more often for words related to a S's emotional conflicts (critical) than to words which are not so related (neutral). An experimental group of 26 college males and females under hypnosis learned individualized lists of 9 critical and 9 neutral words selected from a word-association test, and were then given posthypnotic amnesia for 10 of the 18 words, without instruction as to what words they would forget. A control group received similar treatment without hypnosis. In support of the hypothesis, the experimental group forgot a significantly greater number of critical over neutral words. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodermal measures in experimental amnesia.

14 Ss equated with respect to hypnotizability were subjected to electrodermal orienting response (OR) adaptation to tone stimulation. ? the Ss were hypnotized, ? were not. Adaptation of the OR was conducted under hypnosis, with suggestion of amnesia both under hypnosis and as a posthypnotic suggestion. The control group yielded progressive adaptation curves, while "amnesia" produced a lifting of the adaptation. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term memory in autism spectrum disorder.

Three experiments examined verbal short-term memory in comparison and autism spectrum disorder (ASD) participants. Experiment 1 involved forward and backward digit recall. Experiment 2 used a standard immediate serial recall task where, contrary to the digit-span task, items (words) were not repeated from list to list. Hence, this task called more heavily on item memory. Experiment 3 tested short-term order memory with an order recognition test: Each word list was repeated with or without the position of 2 adjacent items swapped. The ASD group showed poorer performance in all 3 experiments. Experiments 1 and 2 showed that group differences were due to memory for the order of the items, not to memory for the items themselves. Confirming these findings, the results of Experiment 3 showed that the ASD group had more difficulty detecting a change in the temporal sequence of the items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social psychological factors in the genesis of posthypnotic source amnesia.

Three experiments assessed the role of social psychological variables in source amnesia. Experiment 1 found that low-hypnotizable subjects instructed to simulate partial amnesia were more likely to exhibit source amnesia than high-hypnotizable hypnotic or task-motivated subjects. Experiment 2 found equivalent rates of source amnesia in low-hypnotizable simulators and high-hypnotizable hypnotic subjects. In addition, the findings of Experiment 2 failed to support the idea that the instructions for partial amnesia given to simulators cued for the occurrence of source of amnesia as well as for the occurrence of partial amnesia. In Experiment 3, preliminary instructions that legitimated source amnesia as a role-appropriate response produced significantly more posthypnotic source amnesia than did neutral or no instructions. Together, the findings of the 3 experiments support the relation of source amnesia to experimental demands and subjects' expectations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analgesic effects of posthypnotic suggestions and virtual reality distraction on thermal pain.

The individual and combined effects of posthypnotic suggestion (PHS) and virtual reality distraction (VRD) on experimentally induced thermal pain were examined using a 2 × 2, between-groups design. After receiving baseline thermal pain, each participant received hypnosis or no hypnosis, followed by VRD or no VRD during another pain stimulus. Consistent with the hypothesis that hypnosis and VRD work via different mechanisms, results show that posthypnotic analgesia was moderated by hypnotizability but VRD analgesia was not. The impact of PHSs for analgesia was specific to high hypnotizables, whereas VRD was effective independent of hypnotizability. Results also show a nonsignificant but predicted pattern for high hypnotizables: Audio hypnosis combined with VRD reduced worst pain 22% more and pain unpleasantness 25% more than did VRD alone. Theoretical and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnosis and psychopathology: Retrospect and prospect.

As an editorial introduction to a special issue on hypnosis and psychopathology, this article discusses several links between the 2 fields. Historically, observation of the parallels between hypnosis and hysteria played an important role in the discovery of unconscious mental processes, the development of psychogenic theories of psychopathology and the rise of psychotherapy. It is proposed that hypnotic anesthesia and analgesia, amnesia, and posthypnotic suggestion may serve as laboratory models of dissociative phenomena seen in the clinic. Furthermore, hypnosis may be useful in the exploration of processes involved in emotional response and the formation of hallucinations and delusions. With respect to personality and behavior change, hypnosis has commonly been employed in the treatment of pain and habit disorders by means of direct suggestion, but its use is not limited to suggestive therapeutics. Hypnotic relaxation, images and dreams, suggested amnesia, hypermnesia, and age regression may be useful in both psychodynamic and cognitive-behavioral therapies. Possible lines for further research on the relation between hypnosis and both experimental and clinical psychopathology are discussed. (82 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired Implicit Memory for Gist Information in Amnesia.

In 2 experiments using a converging associates paradigm, the authors evaluated implicit memory for gist information in amnesic patients. In Experiment 1, participants saw multiple sets of associates, each converging on a nonpresented theme word, and were then tested using an implicit word stem completion test and an explicit cued recall test. Amnesic patients showed intact implicit and impaired explicit memory for studied words, but memory for nonpresented lures was impaired, regardless of retrieval instructions. To evaluate whether impaired implicit memory for lures was due to accelerated forgetting of gist information, short study lists were used in Experiment 2, each consisting of a single set of associates. Amnesics' implicit memory for lures was again impaired. These results point to an inability to encode robust gist representations as the cause of impaired gist memory in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)