According to recent findings, interhemispheric interactions and information connectivity represent crucial mechanisms used in processing information across various sensory modalities. To study these interactions, the authors measured bilateral electrodermal activity (EDA) in 33 psychiatric outpatients. The results show that during congruent Stroop stimuli in hypnosis the patients with higher hypnotizability manifest a decreased level of interhemispheric information transfer measured by pointwise transinformation (PTI) that was calculated from left and right EDA records. These results show that specific shifts of attentional focus during hypnosis are related to changes of interhemispheric interactions that may be reflected in neural connectivity calculated from the bilateral EDA measurement. This attentional shift may cause dissociated attentional control disturbing integrative functions of consciousness and contextual experiences.
Hypnosis has had a gradual conceptual emergence from an alleged mystical experience, to sleep, to a psychological shift in concentration that activates a preexisting neuro-physiological circuitry. Data is presented to support the thesis that hypnotizability exists on a spectrum that has biological as well as psycho-social components. When there is synchrony between the bio-psycho-social components of hypnotizability as measured by the Hypnotic Induction Profile (an intact flow), psychotherapy is the primary treatment strategy, with medication secondary or not at all. When measurement reveals a lack of synchrony between biological factors as measured by the eye-roll sign and psycho-social responsivity (a nonintact flow), medication will be primary, with different degrees of psycho-social support.