Corpus callosum size, hypnotic susceptibility and empathy in women with alleged mediumship: a controlled study.

Alleged mediums who report regular communication with deceased personalities show no differences in brain structure, hypnotizability, dissociation, or empathy compared to non-medium controls. Magnetic resonance imaging revealed normal corpus callosum areas in the medium group, contrasting with abnormalities seen in psychotic and dissociative disorders. Both groups had intermediate hypnotic susceptibility levels, and the rostrum of the corpus callosum area did not correlate with hypnotizability. The medium group reported more anomalous experiences but scored similarly on dissociation, empathy, and mental health measures. The findings suggest that mediumship is not associated with the brain abnormalities or dissociative pathology found in clinical conditions.

Study at a glance

Abstract

Evidence indicates that highly hypnotizable subjects may have larger area of the rostrum of the corpus callosum (CC). Mediumship can be defined as the alleged ability to communicate regularly with deceased personalities, and self-hypnosis is postulated as an underlying mechanism for this ability. Therefore, we aimed to investigate the CC area, hypnotic susceptibility, self-reported dissociation, and empathy in alleged mediums in comparison with healthy, non-medium controls. The study sample consisted of 16 Spiritist mediums (medium group (MG)) and 16 non-medium controls. Magnetic resonance imaging scans were performed to measure the CC areas (total and subdivisions). The Harvard Group Scale of Hypnotic Susceptibility was used to assess hypnotizability, and self-reported measures were used to investigate anomalous experiences, mental health using the Self-Reporting Questionnaire-SRQ, dissociative experiences using the Dissociative Experiences Scale, and empathy using the Interpersonal Reactivity Index. No between-group differences were found in the total or subdivided CC areas or in hypnotizability, with both groups showing intermediate levels. The rostrum of the CC area and hypnotizability were not correlated. The MG presented with significantly more anomalous experiences, but the two groups had similar scores for dissociation, empathy, and mental health. The normal CC areas found in the MG are in contrast with the abnormal results typically observed in subjects with psychotic and dissociative disorders. Although hypnotizability was not different between groups, further studies are needed to replicate these findings in other samples.