Functional neuroanatomy of hypnotic state

Background: The aim of the present study was to describe the distribution o f regional cerebral blood flow during the hypnotic state (HS) in humans, us ing positron-emission tomography (PET) and statistical parametric mapping, Methods: The hypnotic state relied an revivification of pleasant autobiogra phical memories and was compared to imaging autobiographical material in "n ormal alertness." A group of 9 subjects under polygraphic monitoring receiv ed six (H2O)-O-15 infusions and was scanned in the following order: alert-H S-HS-HS with color hallucination-HS with color hallucination-alert. PET dat a were analyzed using statistical parametric mapping (SPM95). Results: The group analysis showed that hypnotic state is related to the ac tivation of a widespread, mainly left-sided, set of cortical areas involvin g occipital, parietal, precentral, premotor, and ventrolateral prefrontal c ortices and a few right-sided regions: occipital and anterior cingulate cor tices. Conclusions: The pattern of activation during hypnotic state differs from t hose induced in normal subjects by the simple evocation of autobiographical memories, It shares many similarities with mental imagery, from which it d iffers by the relative deactivation of precuneus, Biol Psychiatry 1999;45:3 27-333 (C) 1999 Society of Biological Psychiatry.