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)     

"Reduced clustering during hypnotic amnesia for a long word list: Comment on Wilson and Kihlstrom": Rejoinder to Spanos, Bertrand, and Perlini.

In their comment on Kihlstrom and Wilson's (1986) failure to find disorganized clustering in posthypnotic amnesia, Spanos, Bertrand, and Perlini (1988) commit a number of factual errors, and misinterpret and misrepresent both our findings and their own. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal sequencing during posthypnotic amnesia: A methodological critique.

In studies by F. J. Evans and J. F. Kihlstrom, (1973, 1975, 1979), using the susceptibility-scale paradigm, high susceptibles (HSs) were less likely than low susceptibles (LSs) to recall the events of the hypnotic session in temporal sequence (i.e., temporal disorganization effect) following an amnesia suggestion. The primary measure of recall order was the rank-order correlation (rho scores) between the presentation order and the recall order of hypnotic experiences computed for each S. Following a suggestion for posthypnotic amnesia, HSs usually obtained lower rho scores than LSs. This research is critically examined, noting methodological shortcomings associated with the susceptibility-scale paradigm, inconsistent findings, and failures to replicate. Two studies are described that found no relationship between susceptibility level and rho scores. These null results held true for Ss who recalled new information after cancellation of the amnesia suggestion (reversers) as well as for those who did not recall new information (nonreversers). Nevertheless, the authors have replicated previous work on differential recall of the 1st item. (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)     

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)     

The impact of videotape playback of hypnotic events on posthypnotic amnesia.

Examined the breakdown of amnesia by showing 48 hypnotic and nonhypnotic undergraduates (Harvard Group Scale of Hypnotic Susceptibility) a videotape of the hypnotic events they had experienced. The extent of the amnesia for these events was defined precisely, and simulating procedures were employed to analyze the cues in the overall test situation. Videotape display of the hypnotic events was presented via the Experiential Analysis Technique and served to optimize conditions for breakdown. Some hypnotic Ss' amnesia could not be broken down even though they were exposed via videotape playback to the events to be recalled and when suggestions for the period of amnesia were quite explicit. Simulators showed breaching of amnesia but attributed their recall to the videotape rather than to the hypnotic session. Hypnotic Ss were distinctive in their inability to recall experiential aspects of their performance even though they could recall behavioral aspects. The data are discussed in relation to the hypothesis that dissociative cognitive mechanisms underlie posthypnotic amnesia. (22 ref) (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)     

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)     

Effects of social-psychological variables on hypnotic amnesia.

Three experiments with 196 undergraduates assessed the hypothesis that suggested amnesia for a previously learned word list is a function of Ss' interpretations of the ambiguous aspects of the amnesia testing situation. By manipulating preliminary instructions concerning interpretations of this situation, Ss who were unselected with respect to hypnotic susceptibility (measured by the Harvard Group Scale of Hypnotic Susceptibility, Form A) were induced to show either substantial increments or decrements in amnesia. However, Ss high on hypnotic susceptibility ignored preliminary instructions and therefore could not be induced to show decrements in amnesia. Previous findings of more amnesia in hypnotic than in task-motivated Ss were both replicated and reversed by varying their interpretations of the amnesia task. Analyses of the data confirmed earlier findings that partial amnesics tend to recall list items in a relatively disorganized fashion. Findings are consistent with an inattention hypothesis of suggested amnesia. (31 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)     

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)     

Hypnosis and psychopathology: Replacing old myths with fresh metaphors.

Argues that theories of psychopathology and theories of hypnosis as a special state have been flawed by the unwitting joining of 2 mutually exclusive metaphysical systems: formism and mechanism. To support this assertion, the present paper examines the context of late-19th-century attempts to explain hypnotic phenomena and abnormal conduct. Amnesia has been cited as support for hypnosis as a special state of mind and for psychopathology as mental sickness. To support this contextualist critique, contemporary research on hypnotic amnesia is reviewed. The fact that conditions can be arranged to influence some amnesic Ss and patients to breach amnesia throws doubt on the explanatory power of disordered or disarranged minds. The conventional formist–mechanist explanation lacks categories to help understand the breaching of amnesia. A conception of amnesia as intentional action is proposed, and how the intentions are carried out is discussed. The analysis leads to the notion that amnesia is a form of rhetorical communication. Because intentions play a part in hypnotic and hysterical amnesia, explanatory concepts borrowed from the study of strategic interaction are useful in explaining the breaching of hypnotic amnesia. Among these concepts are secrets, deception, and self-deception. (62 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotic amnesia and the paradox of intentional forgetting.

Hypnotic amnesia is often interpreted as a deliberate effort to avoid thinking of ideas or thoughts targeted for amnesia. However, as D. M. Wegner (1989) showed, nonhypnotized individuals who deliberately attempt to suppress certain thoughts or images paradoxically suffer intrusions of the proscribed material. The authors replicated Wegner's findings in 2 separate investigations. However, they also found that hypnotic amnesia did not have such paradoxical effects. Indeed, the great majority of high-hypnotizable individuals administered suggestions for amnesia showed no such intrusions whatsoever, indicating that thought suppression and hypnotic amnesia represent quite different processes. (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)     

Toward a theory of "hypnotic" behavior: Experimental analyses of suggested amnesia.

Suggestions of amnesia were given to 144 Ss in a 2 X 2 X 4 factorial experiment. The independent variables were: (1) spoken vs. recorded presentation of suggestions, (2) presence vs. absence of hypnotic induction, and (3) 3 types of suggestions for amnesia—authoritative ("You will not rememberp"), permissive ("Try to forget"), suggestions to simulate, and no suggestions. Variable 1 did not produce important differences in amnesic performance. Variable 2 significantly affected 1 of the 5 tests for amnesia, with the presence of hypnotic induction resulting in less amnesia. Variable 3 exerted the most powerful effect. Irrespective of the presence or absence of hypnotic induction, Ss differed on the tests for amnesia depending on which suggestion they were given. (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)     

Hypnotic amnesia and temporal organization: Effects of learning set, stimulus type, number of presentations, and hypnotic susceptibility.

Examined the effects of learning set, type of critical material, number of list presentations, and hypnotic susceptibility on the relationship between hypnotic amnesia and seriation in 3 experiments with 268 undergraduates. In Study 1, the critical stimuli were hypnotic test suggestions, and Ss were exposed to either an incidental or intentional learning set. Study 2 again manipulated learning set, but words served as the critical stimuli. Study 3 involved single vs multiple word list presentations prior to amnesia testing. No evidence for an amnesia-specific breakdown in seriation was obtained, and no consistent relationship between hypnotic susceptibility and changes in organization across recall trials emerged. Findings suggest that learning set, stimulus materials, and number of presentations could not account for the discrepant results obtained with the susceptibility scale and word list paradigms. (French abstract) (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)     

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)     

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)