Post‐hypnotic amnesia: Seeing is not remembering

Abstract

Prior to the administration of the reversibility cue to cancel a suggestion for post-hypnotic amnesia, subjects were exposed to a videotape playback of the events of the hypnotic session in the presence of an independent experimenter. The specific application of this method (the Experiential Analysis Technique) was designed to maximally cue subjects to recall and report on amnesic events. Performance of highly susceptible subjects who viewed the videotape indicated that amnesic subjects commented on fewer items, stopped the videotape less, and verbalized less than did non-amnesic subjects. The cued recall of the amnesic group was also often item-specific rather than general, and allowed one to distinguish between the impact of behavioural and experiential events. For some subjects, amnesia clearly could not be completely broken by the presentation of maximal cueing.

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

“…Subjects were then instructed to close their eyes, were administered a standard hypnotic induction and tested on a range of hypnotic tasks (hand lowering, arm immobilization, age regression, glove analgesia, missing number, hallucination, and missing watch hand; since the glove analgesia and hallucination items included nonroutine aspects, the hypnotic score obtained by subjects was based on the remaining five items), and were finally administered the suggestion for posthypnotic amnesia. The posthypnotic amnesia suggestion was similar to that employed in previous research (see McConkey et al, 1980), with the important modification that instructions communicated explicitly the limits of the suggestion in order to test whether the maintenance of amnesia for some hypnotic subjects was an artifact of the context of suggestion defined in the previous study. The verbatim suggestion was as follows (aspects designed to limit the framework of the suggestion are italicized):…”

“…One aim of the present study was to determine whether an ambiguity in the instructions employed in the study by McConkey et al (1980) led hypnotic amnesic subjects to maintain their amnesia performance following the viewing of the videotape. An amnesia instruction that specified more closely the period of amnesia was used in the present study in order to test this possibility.…”

“…The presentation of a videotape playback of the hypnotic events could be said to serve, in a sense, as a variant of recognition testing for subjects' memories of the hypnotic events in which the number of times subjects stop to comment on their recall of the hypnotic events can be taken as an approximate index of their recognition memory (see Kihlstrom & Shor, 1978;and Williamsen, Johnson, & Eriksen, 1965; for a discussion of recognition memory during posthypnotic amnesia). The findings of McConkey et al (1980) indicated that almost half of the initially amnesic subjects maintained their amnesia response after viewing (on videotape) the events as they had taken place. Close inspection of the data, however, indicated that some subjects may have perceived the amnesia suggestion as extending over the total session; that is, the procedures for breaching amnesia may not have affected subjects in a uniform or consistent manner.…”

“…One line of research that promises to provide important evidence is the attempt to break down, or breach, posthypnotic amnesia prior to its reversal. Studies adopting this method of inquiry (e.g., Bowers, 1966;Howard & Coe, 1980;Kihlstrom, Evans, Orne, & Orne, 1980;McConkey, Sheehan, & Cross, 1980;Schuyler & Coe, in press) appear to indicate that amnesia can be broken down for some, but not all, subjects. Studies have varied substantially, however, in the degree of demand for breakdown that they have provided.…”

“…Across these studies the specific test conditions employed had little differential impact on the amnesia performance of subjects; individual differences in hypnotizability and previous amnesia performance were far more important factors in determining the outcome of attempts to break down the amnesia. McConkey et al (1980) placed the most stringent demands on subjects to breach their amnesia by showing them a videotape of their hypnotic session prior to the administration of the reversibility cue. Specifically, the study involved an application of the Experiential Analysis Technique (EAT; Sheehan, McConkey, & Cross, 1978), which is a technique developed to facilitate and inquire into subjects' retrospective recall of hypnotic events.…”