The Hypnotized Brain: An Examination of the iEEG Correlates of Neutral Hypnosis

FREEDMAN S.; MATEOS D.; GOMEZ-RAMIREZ J.; PEREZ VELAZQUEZ, J.L.; VALIANTE TAUFIK

Toronto

Conferencia; 11 th National conference of Canadian Association for Neuroscience; 2016

Canadian Association for Neuroscience

p { margin-bottom: 0.21cm; direction: ltr; color: rgb(0, 0, 0); }p.western { font-family: "Times New Roman",serif; font-size: 10pt; }p.cjk { font-family: "Times New Roman",serif; font-size: 10pt; }p.ctl { font-family: "Times New Roman",serif; font-size: 10pt; }This research investigates theneurophysiological mechanisms of hypnosis using intracranialelectroencephalography. This methodology removes resolution problemsassociated with functional imaging. Patients with intractableepilepsy, and implanted as part of their diagnostic exam, werehypnotized. Neutral hypnosis was measured following a standardinduction procedure, and before the administration of hypnoticsuggestions. Patients with high and low hypnotizability were testedand compared. Phase based synchronization for connectivity analysiswas calculated for three different conditions: prehypnotic state(eyes open and closed), neutral hypnosis (eyes closed) andposthypnotic state (eyes open and closed), across multiple frequencybands. The intersite phase clustering difference between all theintracranial electrodes across delta, theta, alpha, beta and gammafrequencies, was computed for all conditions. In high hypnotizablepatients with bi-temporal burr holes, we found more intersitesynchronization, for theta and alpha bands, in the hypnotic conditionthan in the eyes closed conditions, and a more modular organization(more partitionable) in both the hypnotic and the eyes closedconditions, compared to the eyes open conditions. Phasesynchronization distribution distance for all bands between hypnoticand posthypnotic states was shorter in high than in low hypnotizablepatients. Our results suggest that hypnosis represents a genuinebrain state whose distinctiveness from states of deep relaxation isin need of clarification.