P300 event-related-potential amplitudes and evoked cardiac responses during hypnotic alteration of somatosensory perception

Abstract

Ten highly hypnotizable women and 10 women with low hypnotizability were tested in a sometosensory target detection task to evaluate the effects of hypnotic alterations of somatosensory perception on P3 peak amplitude and evoked cardiac response. Stimulus detection task consisted of standard and target electric stimuli delivered with a fixed foreperiod. The P3 peak amplitude of ERPs recorded from frontal, central and temporo-parieto-occipital (posterior) scalp sites and phasic heart rate deceleration response were compared in four conditions: (1) normal attention in waking state, (2) hypnotic obstuctive hallucination, (3) hypnotic attention, (4) hypnotic passive attention. High hypnotizable subjects demonstrated suppression of P3 peak amplitude to target stimuli in the left frontal and posterior scalp sites during hypnotic obstructive hallucination as compared to a normal attention condition. In this condition P3 suppression was paralleled by a smaller anticipatory heart rate deceleration response to probe stimulus onset. The P3 peak to standard stimuli was found significantly greater in low hypnotizable subjects than for those with high hypnotizability regardless of condition. These findings demonstrate that hypnotically induced obstructive hallucination to somatosensory stimuli involve alterations in neural and autonomic response and are consistent with a trait conception of hypnotizability.