Enhanced Afterimage Persistence in Waking and Hypnosis: High Hypnotizables Report More Enduring Afterimages

Abstract

This study investigated the moderating influences of hypnotic susceptibility level (high/low) and visuospatial skill level (high/low) on afterimage persistence in waking and hypnosis. All Ss were administered the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A; [1]), the Group Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C; [2]), and the Mental Rotations Test (MRT; [3]). In counterbalanced sessions of waking and hypnosis, 80 Ss (20 high/high, 20 high/low, 20 low/high, 20 low/low) were dark adapted for twenty minutes each, after which a brief flash of light was presented. Visuospatial skills, as measured by the MRT, did not significantly influence first afterimage intervals or afterimage durations. High hypnotizables reported significantly longer first afterimage intervals and afterimage durations in hypnosis than did low hypnotizables. High hypnotizables reported significantly longer first afterimage intervals, but not afterimage durations, in waking than did low hypnotizables. High hypnotizables reported significantly longer afterimage durations and first afterimage intervals in hypnosis than in waking. Low hypnotizables reported similar afterimage durations and first afterimage intervals in waking and hypnosis. Implications of these results for the ability of high hypnotizables to focus attention upon and maintain valid visual images are discussed.