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)     

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)     

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)     

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)     

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)     

Paired-associate learning and priming effects in amnesia: A neuropsychological study.

Conducted 4 experiments investigating the role of priming effects in paired-associate learning. Ss for all 4 experiments were 5 male and 3 female alcoholics (mean age 53.8 yrs; WAIS—R IQs 85–203) with Korsakoff syndrome. Control Ss were 26 male alcoholics (mean age 47.6 yrs). Exp I illustrated the distinction between the memory impairment of amnesic (Korsakoff) Ss and their intact priming ability. In Exp II, amnesic Ss showed good paired-associate learning for related word pairs but controls performed significantly better. Exp II also showed that the forgetting of related word pairs by amnesic Ss followed the same time course as the decay of word priming. Exp III showed that amnesic Ss were as good as controls at learning related word pairs when word-association tests were used. Exp IV showed that amnesic Ss exhibited normal priming when they were asked to free associate to words that were semantically related to previously presented words. Results indicate that both priming effects and paired-associate learning of related words depended on activation, a process that is preserved in amnesia. Activation is a transient phenomenon presumed to operate on and facilitate access to preexisting representations. (67 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of retrieval cues in breaching hypnotic amnesia.

We conducted this study to determine whether hypnotically amnesic subjects would breach amnesia when forced to attend to powerful retrieval cues. Following a standard hypnotic induction procedure, 113 subjects attempted to recall a 48-item word list. The list consisted of instances of taxonomic categories presented in blocked format and was presented only once. A forced-recall procedure required subjects to recall 48 items even if that involved guessing. Next, 85 subjects were administered an amnesia suggestion and recalled the list a second time. The remaining 28 subjects served as controls and recalled the list a second time without the intervening suggestion. On Trial 3, the breaching trial, subjects were given the 12 category names and were required to recall 4 items under each. Finally, the suggestion was canceled for subjects in the suggestion condition, and all subjects completed a final cued recall. Subjects in the suggestion condition who showed amnesia on the second trial breached completely on Trial 3. We argue that the task demands prevented them from using the cognitive strategies that, under other circumstances, maintain amnesia. Limitations of the present study and suggestions for further research are discussed. (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)     

Episodic and semantic memory in posthypnotic amnesia: A reevaluation.

J. F. Kihlstrom (see record 1980-11245-001) hypothesized that posthypnotic amnesia involved a dissociation between episodic and semantic components of memory. The present study tested an alternative hypothesis that Kihlstrom's findings resulted from experimental demands conveyed by the wording of the amnesia suggestion he employed. It was hypothesized that hypnotically amnesic Ss would show performance deficits on semantic and episodic memory tasks if expectations for such deficits were subtly conveyed to them. Using 2 treatment conditions, 60 undergraduates were divided into susceptibility groups. Condition 1 replicated Kihlstrom's experiment; in Condition 2, Ss were given an alternative hypnotic suggestion. It was found that Ss could be induced to show only episodic impairments (thereby replicating Kihlstrom) or both episodic and semantic impairments (contrary to Kihlstrom) by subtly varying the wording of amnesia suggestions. Findings are inconsistent with a dissociation hypothesis. Instead, they support the notion that hypnotic amnesia is a strategic enactment strongly influenced by expectations generated in the amnesia testing situation. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The hidden observer in hypnotic analgesia: Discovery or experimental creation?

Eight highly susceptible (Harvard Group Scale of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scale) Ss were assigned to E. R. Hilgard and J. R. Hilgard's (1975) training procedures for eliciting "hidden" reports during hypnotic analgesia. These procedures indicate to Ss that a "hidden part" of themselves continues to feel high levels of pain while their "hypnotized part" experiences reduced pain. Eight additional Ss were given the opposite expectation concerning "hidden pain"—that their "hidden part" would feel less pain than their "hypnotized part." Ss expecting high levels of "hidden" pain reported high levels, whereas those expecting little "hidden" pain reported low levels. Results are inconsistent with the notion that "hidden" reports reflect the intrinsic activity of a "dissociated state." Instead, they indicate that "hidden" reports result from Ss' attempts to convincingly enact the role of "good hypnotic S" as this role is defined for them by the experimental procedures they undergo. (55 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)     

Posthypnotic amnesia: Suggestions of an active process in dissociative phenomena.

In a study with 62 undergraduates, a retroactive inhibition design was used to examine the process of posthypnotic amnesia. Ss were assigned to either a posthypnotic amnesia or a no-posthypnotic amnesia treatment group and were administered the 1st 11 items of the Stanford Hypnotic Susceptibility Scale. Results support the notion that "forgotten" material is as available to amnesia Ss at some level as it is to nonamnesic Ss. Further, so-called forgetting appears to be the result of an active process, that is, something the S does. Implications for understanding dissociative phenomena in general are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

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)     

Pain and dissociation in the cold pressor test: A study of hypnotic analgesia with "hidden reports" through automatic key pressing and automatic talking.

To test whether pain blocked by hypnotic analgesia may still be perceived at some level, 20 highly hypnotizable undergraduates participated in an experiment involving cold pressor pain in the normal condition and in hypnotically suggested analgesia. 3 reports were obtained reflecting felt pain within the hypnotic analgesia condition: the usual verbal report on a numerical scale, a manual report by "automatic key pressing," and a retrospective verbal report through "automatic talking." 9 Ss who were amnesic for both keypressing and automatic talking reported more pain in the automatic (hidden) reports than in their usual verbal reports. 8 of these 9, following release of amnesia, had a clear perception of 2 levels of awareness of the pain: the usual hypnotic experience of pain attenuated by analgesia suggestions, and a knowledge at another level of a more severe pain. In no case, however, did an S give a retrospective report of normal suffering at this "hidden" level. The hypnotically analgesic S may have reported no pain verbally because he was amnesic for it; when amnesia was removed he recalled the sensory pain, but without a suffering component, because suffering apparently did not occur. (24 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)     

Increasing contextual pressures to breach posthypnotic amnesia.

The study investigated conditions that produce strong social pressures on posthypnotically amnesic Ss to remember more before being given the cue to remove amnesia. Highly susceptible Ss who passed posthypnotic amnesia were classified as voluntary or involuntary (having high or low control over recall). Test Ss were serially subjected to 3 pressure situations before being given the cue to lift amnesia: (a) instructions to be honest, (b) lie detection, and (c) a replay of a video of the session. Control Ss sat for the same amount of time and were only asked if they could remember anything else while the experimental Ss received pressure recalls. All but 1 S breached in the experimental condition. Only the voluntary Ss breached in the control condition. Results are discussed as they relate to breaching amnesia and the voluntary dimension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is the hypnotized subject lying?

Do the verbal reports of deeply hypnotized Ss truthfully reflect their subjective experiences of hypnotic suggestions? Exp 1 established that the electrodermal skin conductance response (SCR) provides an effective method for detecting deception in the laboratory equally well in hypnotized and nonhypnotized Ss. In Exp 2, deeply hypnotized and simulating Ss were administered a number of hypnotic suggestions in a typical hypnotic session, without mention of deception, and were questioned about their experiences while SCR measures were recorded concurrently. Results indicate that 89% of the hypnotized Ss' reports met the criterion for truthfulness, whereas only 35% of the simulators' reports met this criterion. Implications for the theory of hypnosis are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective hypnotic amnesia: Is it a successful attempt to forget or an unsuccessful attempt to remember?

Ss in 2 experiments (ns?=?72 and 50) learned a 16-item, 4-category word list and were then administered hypnotic suggestions to be amnesic for all the words in 1 of the categories. Even when selective amnesia was completely successful, Ss in both experiments revealed a high level of recall for words not targeted for amnesia; moreover, these words were recalled in a highly organized, category-by-category fashion. Evidently, attention to relevant retrieval (i.e., organizational) cues does not oblige recall of words targeted for amnesia. Forgetting in the presence of such powerful mnemonic cues seems to characterize hypnotic amnesia and some spontaneous forms of forgetting as well. We argue that mnemonic lapses of this kind represent a failed attempt to remember rather than a successful attempt to forget. (PsycINFO Database Record (c) 2010 APA, all rights reserved)