Frontal functions, connectivity and neural efficiency underpinning hypnosis and hypnotic susceptibility

An update is provided of an earlier review (Gruzelier, 1998) of the range of evidence for neurophysiological changes in frontal and lateralized functions with hypnosis, changes which have differentiated high from low hypnotically susceptible subjects, and which led to a working model and neuropsychological translation of the hypnotic induction process. New evidence is outlined from an fMRI/EEG study. This study also disclosed the importance of neural efficiency in left lateral frontal and anterior cingulate structures, and their connectivity, for distinguishing high from low hypnotic susceptibility both in hypnosis and in the everyday state. This amplifies earlier constructs such as cognitive flexibility. Though the focus will be largely on the alteration of connections with the anterior brain and its corresponding alterations of function, interhemispheric, posterior and subcortical connectivity is also considered. The practical implications for the interaction between the hypnotherapist and subject are considered, including stage hypnosis.