The aim of the study was to investigate the EEG and autonomic concomitants of the hypnosis, internal imaging and emotional experience.
13 high hypnotizable subjects participated in two experiments: (1) in hypnotic session (HS) that included
live hypnotic induction, deep hypnotic relaxation, recollection of emotionally indifferent (I), positive (P) and
negative (N) past events and (2) in a waking session (WS) that included inner silence condition, and recollection of the same I, P, N past events. To explore the dimension of the affect intensity two modes of the emotional events recollection were used in WS - “associated” (A - active participation of the subject in the remembered event) and “dissociated” (D - watching of the event “at the inner screen”). EEG (19 sites), ECG and skin conduction (SC) were recorded.
Heart rate and SC changes during HS and WS paralleled the anticipated increase of arousal level from relaxation to inner imagery and further to P and N emotion recollection, thus verifying the emotional experience. The observed decrease of EEG spectral power (SP) and coherence (COH) within all frequency bands under HS may reflect the specificity of hypnosis as an altered state of consciousness. Mental imagery led to pronounced blockage of alpha SP over the posterior scalp area. During emotional conditions the generalized increase of EEG SP was observed. Delta and theta SP increase was more pronounced during N emotions, whereas alpha SP increase – during P ones. Beta2 and gamma1 SP was higher at right frontal, central and parietal sites during P emotions as compared to N ones. Emotion-related patterns of COH changes were frequency as well as hemispheric-specific depending on emotional valence. P emotions elicited more pronounced right-hemispheric COH increase within gamma bands. N emotions led to greater increase of left-hemispheric COH within theta and beta1 bands. EEG changes in WS had the same direction but were less pronounced than in HS. The SP and COH differences between A and D recollections of events in WS were revealed in the bands specifically depending on emotional valence. D mode as compared to A one led to less gamma SP during P event recollection, to higher alpha1 and alpha2 SP during N event and to less theta, beta and gamma COH during both emotional event recollection.
The obtained results corroborate and extend the existing findings of the role of EEG rhythms in hypnotic state and emotion production.
T. Stroganova, A.Kirenskaya, V. Novototsky-Vlasov, A. Chistyakov, M.Tsetlin, V.Zvonikov. EEG study of mental imagery and emotion production during hypnosis. Int. J. Psychophysiol., 2006, v.61, N3, P. 359. (13th World Congress of Psychophysiology, Istanbul, Turkey, 2006).; V.Zvonikov, .Kirenskaya, V.Novototsky-Vlasov, T. Stroganova, A.Chistyakov. The study of autonomic variables’ changes during emotional experience of different intensity. Symposium «Psychotherapy in the system of medical sciences in the making of evidence based practice », St. Petersburg, Russia, 2006 (in Russian).; A.Chistyakov, .Zvonikov, A.Kirenskaya, V. Novototsky-Vlasov. The study of autonomic variables’ changes during recollection of emotionally loaded past events. Symposium “Professional longevity and quality of life”. Moscow, 2007, p.237-238 (in Russian).
|Secondary author(s): |
|Stroganova, T. A., Tsetlin, M. M., Kirenskaya, A., Novototsky-Vlasov, V. Y., Marushkina, A.|
|Zvonikov, V. M., Stroganova, T. A., Tsetlin, M. M., Kirenskaya, A., Novototsky-Vlasov, V. Y., Marushkina, A. (2008). Imagery and emotion production during hypnosis: an electrophysiological approach. In Aquém e além do cérebro. Behind and beyond the brain. Proceedings of the 7th Symposium of Fundação Bial. Porto: Fundação Bial.|