Howard Shevrin

Visual evoked response correlates of unconscious mental processes

Average evoked responses and accompanying free associations elicited by subthreshold visual stimuli were studied to determine if a differential discrimination between two stimuli would be reflected in either or both of these responses. The results indicate that the effects of subliminal perception are encoded in the average evoked response and also influence the content of free associations.

Brain Response Correlates of Repressiveness

Averaged evoked responses (AER) to tactile stimulation were compared for two groups of same-sex adolescent twins. An experimental group consisted of 5 pairs of twins who differed in repressiveness ratings based on the Rorschach; a control group consisted of 5 pairs of twins who were identical in repressiveness ratings. Significant amplitude differences (p < .01) were found for three components of the AER for the twins who differed in repressiveness while comparable differences were not found for the control group. Sensitivity to the ideational effects of a subliminal visual stimulus was found to be associated with low repressiveness (p < .05). These findings support the hypothesis that repressiveness is reflected in an intensification of attention directed to neutral external stimuli as demonstrated by an increase in amplitude of AER components previously found to be associated with attentional processes and a decrease in attention to internal, ideational processes as reflected in low sensitivity to subliminal inputs.

Different effect of an auditory stimulus as a function of rapid eye movement and non-rapid eye movement sleep.

Subjects were stimulated by a specially arranged auditory stimulus during rapid and non-rapid eye movement (REM and NREM) sleep. This stimulus can elicit primary and secondary process levels of responses. Analysis of the sleep reports showed that the stimulus influenced the content of NREM reports on a conceptual level—which is assumed to be related to secondary process thinking—while for REM reports this effect was not present. The results of this study support the hypothesis of different levels of thought organization associated with REM and NREM sleep.

A comparison of dream recall in wakefulness and hypnosis

Abstract The state of consciousness during recall of dreams is an important variable that has not been sufficiently studied, as it might throw light on the recovery process itself. Data from 3 related experiments are presented in which the recall of natural dreams of the previous night is compared for hypnosis and the waking state. The findings support the hypothesis that dreams are more readily recalled in hypnosis than in the waking state. The waking state following hypnosis shows significantly more dream recalls than when waking state precedes hypnosis. This indicates that once hypnosis brings about the recall of a dream, dream memory remains more readily available. It is suggested that the similarity in the nature of the thought processes underlying the dreaming state of sleep and hypnosis is responsible for the improved recall.

Hypnosis as a method for investigating unconscious thought processes: A Review of Research

YPNOSIS HAS PLAYED an important role in the discovery of unconscious processes and in revealing the similarities in thinkH ing shared by neurotic symptoms, dreams, and parapraxes. Yet, after an auspicious beginning as a therapy (2), and after making its debut as a research method some few years later (25), hypnosis has been largely abandoned as a form of treatment and its value in investigating unconscious mental processes has been only intermittently exploited. The purpose of this paper is to review and evaluate a number of studies and experiments in which hypnosis has been used to study unconscioys mental processes of a kind which, we believe, traces its ancestry back to Anna O.’s “chimney sweepings.” In the history of clinical hypnosis, Charcot, Bernheim, and in particular, Breuer and Freud each made fundamental contributions. The singular contribution of Charcot was his use of hypnosis to reproduce behavior which simulated naturally occurring hysterical symptoms. By giving his subjects direct suggestions in hypnosis to experience anesthesias and paralyses he proved that these symptoms were the result of specific ideas holding sway in the patient’s mind. In his obituary of Charcot, Freud (8) granted to Charcot “for all time . . . the fame of having been the first to