Restricted use of success cues in retrieval during posthypnotic amnesia.

Evaluated memory for successful and unsuccessful responses to hypnotic suggestions in partially amnesic Ss and in those Ss with normal forgetting. Two analyses (278 undergraduates) demonstrated that highly hypnotizable Ss experiencing partial posthypnotic amnesia tended to show no selective recall for their successes or failures during amnesia, whereas the remainder of the Ss showed definite selective recall of hypnotic success posthypnotically. These findings support F. J. Evans and J. F. Kihlstrom's (see record 1974-06307-001) hypothesis that posthypnotic amnesia involves a disruption of memory organization and suggest that the phenomenon may be mediated by a restriction in the use of normally employed retrieval cues. (37 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)     

Residual effect of suggestions for posthypnotic amnesia: A reexamination.

Despite the significant recovery of memory observed after suggestions for posthypnotic amnesia are canceled, there still remains an apparent deficit in total recall (after amnesia has been lifted) among Ss who show amnesia on initial testing. This effect, reported originally by E. R. Hilgard and L. S. Hommel (1961), was confirmed in analyses of recall data from groups of 691 and 488 volunteer college students (Exps I and II, respectively) who were administered a standardized, tape-recorded hypnotic procedure. Hypnotizable Ss who initially showed posthypnotic amnesia recalled significantly fewer items after amnesia was removed than did hypnotizable Ss who were initially nonamnesic. Further analysis showed that the residual amnesia effect was not an artifact of the very low level of posthypnotic recall performance shown by pseudoamnesic Ss, failure of memory storage due to such factors as inattention or sleep, or the differential time constraints on the memory reports of previously amnesic and nonamnesic Ss. Residual posthypnotic amnesia may reflect the fact that suggested posthypnotic amnesia, when lifted, takes time to fully dissipate. (16 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)     

Recall and recognition memory during posthypnotic amnesia: A failure to confirm the disrupted-search hypothesis and the memory disorganization hypothesis.

Tested hypotheses that posthypnotic amnesia is characterized by a disruption in the memory search process and, more generally, by disorganization in memory retrieval. 141 undergraduates were administered the Stanford Hypnotic Susceptibility Scales, Forms B and C. Amnesia was assessed by the usual recall criterion and by a batch recognition-testing procedure. The disrupted-search hypothesis, tested by comparing the effects of the amnesia suggestion on recall and recognition, was not supported. The use of recognition items, rank ordered by Ss according to their judgment of order of administration, furnished data to test the memory disorganization hypothesis. In support of this hypothesis, analyses of the temporal rankings of recognized items revealed greater disorganization in the memory of Ss who were initially amnesic by recall criteria than those who were partially amnesic or nonamnesic. Nevertheless, other findings, including the fact that fewer than 50% of the initially amnesic Ss showed disorganized recognition and that the disorganization effect during recall was weak and inconsistent, call into question the explanatory power of this hypothesis. (24 ref) (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)     

Attempting to breach posthypnotic amnesia.

Traditionally, posthypnotic amnesia has been construed as a subjectively compelling deficit in memory retrieval. Alternatively, it may represent a motivated failure to utilize appropriate retrieval cues, lack of effort in recall, active suppression of memory, or unwillingness to verbalize the critical material. In an effort to test the alternative hypothesis of amnesia, 488 college students were presented with 4 kinds of instructions (using 4 modifications of the Harvard Group Scale of Hypnotic Susceptibility, Form A) designed to overcome the effects of suggested posthypnotic amnesia. The instructions particularly affected Ss of low and moderate hypnotizability who failed the criterion for amnesia. For those of moderate and high hypnotizability who met the criterion for amnesia, however, explicit requests for temporal organization, exhortations to maximize recall, and demands for honesty in reporting produced no greater effect on memory than did a simple retest. Results place some boundaries on both the traditional and alternative views of posthypnotic amnesia and invite further exploration of both cognitive and contextual models of the phenomenon. (49 ref) (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)     

Recognition and recall in amnesics.

Examined whether recall is disproportionately disrupted by amnesia compared with recognition, using 7 amnesics (mean age 51 yrs) without a history of alcoholism, 9 amnesic alcoholic Korsakoff syndrome patients (mean age 66 yrs), and 9 controls (mean age 53.2 yrs). It was postulated that if amnesia affects memory uniformly across different direct memory measures, recall of normal controls should not differ from the recall of amnesics when recognition scores of these 2 groups are equated. On the other hand, if recall is disproportionately disrupted, normal recall should be superior to amnesic recall even when recognition is equated. In the present study, amnesic recognition was equated with that of controls by providing amnesics with 8 sec of study time and normal Ss with 0.5 sec. Normal recall was superior to amnesic recall even when no differences were found in recognition. The results further specify the selective nature of amnesia. It is suggested that amnesia reflects a selective disruption of an aspect of memory critical to successful recall. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suggested amnesia and disorganized recall in hypnotic and task-motivated subjects.

Submitted 52 undergraduates to task motivation or hypnotic treatment. Ss were then given an amnesia suggestion for a previously learned list of categorized words. The number of words recalled and the extent to which they were recalled in clusters were compared before, during, and after lifting the amnesia suggestion. Results show that more hypnotic Ss than task-motivated Ss showed amnesia. Furthermore, hypnotic Ss, but not task-motivated Ss, showed less clustering during the suggestion than they did before or after the suggestion. The Ss who showed at least partial failure to recall during the suggestion were classified into 3 groups: (a) those who remembered but did not verbalize the words, (b) those who experienced amnesia as an effortful process involving distraction or forceful suppression, and (c) those who simply relaxed and experienced amnesia as an effortless process. A theoretical model is tentatively advanced to account for these data. (31 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)     

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)     

Some characteristics of posthypnotic amnesia.

This experiment investigated (a) the differences in post-hypnotic amnesic characteristics of Ss with high and low hypnotic susceptibility and (b) the extent of the amnesia. The experimental Ss were presented 6 words under hypnosis with instructions for amnesia. The simulation Ss pretended they were hypnotized and received the words with instructions for posthypnotic amnesia. The control Ss were given the words with instructions only to remember them. Recognition, recall, and associative tests, administered immediately after, assessed the amnesia. Posthypnotic amnesia impaired recall and recognition among the experimental Ss, but did not reduce the availability of the words as associative responses. The simulating Ss overplayed their amnesic role and also showed impaired performance on the associative tests. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotic amnesia as a strategic enactment: Breaching amnesia in highly susceptible subjects.

Proposes that hypnotically amnesic Ss maintain control over their memory processes but often fail to breach amnesia because to do so would conflict with their self-presentation as deeply hypnotized. Two experiments, with 16 undergraduates, demonstrated that highly susceptible hypnotically amnesic Ss could be easily induced to recall all of the "forgotten" target items by defining successful recall as supportive of rather than as inconsistent with a self-presentation as deeply hypnotized. In the 1st part of Exp I, all Ss showed amnesia despite repeated demands to recall honestly. In the 2nd part of Exp I, Ss were led to believe that they possessed a "hidden part" to their mind that remained aware of the target items covered by the amnesia suggestion. Each S recalled all of the forgotten items when the experimenter contacted their hidden part. Exp II replicated this effect and also demonstrated that the characteristics of Ss' hidden reports were a function of the instructions they received and did not reflect the operation of a dissociated cognitive subsystem that subconsciously held the forgotten items. Findings are inconsistent with traditional theorizing about hypnosis, but offer strong support for the hypothesis that hypnotic amnesia is a strategic enactment under the S's voluntary control. (45 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)     

A physiological investigation of volitional and nonvolitional experience during posthypnotic amnesia.

Highly responsive hypnotic Ss (43 undergraduates) who were classified as having control over remembering (voluntaries) or not having control over remembering (involuntaries) during posthypnotic amnesia, were compared with each other on 4 physiological measures—heart rate, electrodermal response, respiration rate, and muscle tension—during posthypnotic recall. Two contextual conditions were employed: One was meant to create pressure to breach posthypnotic amnesia (lie detector instructions) and the other, a relax condition, served as a control. The recall data showed that voluntary Ss under the lie detector condition recalled more than the other 3 samples that did not differ from each other. However, using another measure of voluntariness showed that both voluntary and involuntary Ss breached under lie detector conditions. Electrodermal responses supported Ss' reports of control in this case. Results are discussed as they relate to (a) studies attempting to breach posthypnotic amnesia, (b) the voluntary/involuntary classification of Ss, and (c) theories of hypnosis. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual and conceptual memory processes in global amnesia.

To determine whether global amnesia reflects a selective deficit in conceptual processing, amnesic and control Ss performed 4 memory tasks that varied processing and retrieval requirements. A study-phase modality (auditory/visual) manipulation validated the nature of processing (perceptual and conceptual) engaged by each task. Amnesic patients were impaired on perceptual and conceptual explicit memory tasks (word-fragment and word-associate cued recall) and were intact on perceptual and conceptual implicit memory tasks (word-fragment completion and word association). These results are consistent with the view that limbic-diencephalic structures damaged in amnesia mediate, in part, processes typically engaged during explicit retrieval. The results are inconsistent, however, with the characterization of that deficit as being one of conceptual processing per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organization versus item effects of an elaborated knowledge base on children's memory.

Investigated the extent to which the high levels of recall and organization observed when children are asked to recall their classmates' names (class recall) can be attributed to organizational vs item-specific effects. Ss were 109 1st, 3rd, and 5th graders. Levels of clustering in class recall were elevated when Ss were constrained to recall their classmates' names according to specific organizational schemes (either sex or seating arrangement). However, there was no evidence that changes in levels or styles of organization influenced levels of memory performance or which names were recalled. Results indicate that some of the benefits on memory of an elaborated knowledge base cannot be attributed to differences in organization (either strategic or automatic) but rather are due to differences in the ease with which individual items can be retrieved. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Volitional experiences associated with breaching posthypnotic amnesia.

40 highly responsive hypnotic undergraduates were selected on the basis of the Harvard Group Scale of Hypnotic Susceptibility—Form A and were classified as having control over remembering (voluntaries) or not having control over remembering (involuntaries) during posthypnotic amnesia. Ss rerated their voluntariness after the experiment. Two contextual conditions were employed: a lie detector condition meant to create pressure to breach amnesia and a relaxation control condition. In contrast to earlier findings, the recall data show that both voluntary and involuntary Ss breached under the lie detector condition compared with their counterparts in the relaxation condition, although the degree of breaching was not great in any condition. Results are discussed as they relate to studies attempting to breach posthypnotic amnesia and to characteristics of the voluntary–involuntary dimension. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)