Hypnotic suggestion and the modulation of Stroop interference.

Overview

BACKGROUND: Hypnosis has been used clinically for hundreds of years and is primarily a phenomenon involving attentive receptive concentration. Cognitive science has not fully exploited hypnosis and hypnotic suggestion as experimental tools. This study was designed to determine whether a hypnotic suggestion to hinder lexical processing could modulate the Stroop effect. METHODS: Behavioral Stroop data were collected from 16 highly suggestible and 16 less suggestible subjects; both naturally vigilant and under posthypnotic suggestion. Subjects were urged to only attend to the ink color and to impede reading the stimuli under posthypnotic suggestion. RESULTS: Whereas posthypnotic suggestion eliminated Stroop interference for highly suggestible subjects, less suggestible control subjects showed no significant reduction in the interference effect. CONCLUSIONS: This outcome challenges the dominant view that word recognition is obligatory for proficient readers, and may provide insight into top-down influences of suggestion on cognition.