ABSTRACT
This chapter provides a critical overview of the research linking electroencephalogram (EEG)-assessed oscillations with hypnosis and individual differences in hypnotizability. EEG oscillations reflect the electrical activity of neuronal pools, conventionally classified in bandwidths of frequency oscillations labeled as delta, theta, alpha, beta, and gamma bands. Hypnotic responding has been positively associated with theta band power and, to a lesser extent, with changes in gamma activity, although gamma activity changes during hypnosis show significant effects in both directions. EEG research on functional connectivity indicates that the frequency of EEG oscillations is not central to hypnosis responding and hypnotic susceptibility. A local disruption in the left frontal and long-range functional cortical connectivity in various frequency bands has been reported, depending on the suggestions given and response requirements. Functional connectivity findings are consistent with the dissociated control models of hypnosis in which disruptions in the functional integration between different components of executive control account for hypnosis and hypnotic responding. A reasonable line of inquiry based on the extant EEG findings would be to examine the role of the functional integration of frontal lobes with other cortical regions in hypnosis and hypnosis responsivity.
