HYPNOTIC CATALEPSY-INDUCED CHANGES OF REGIONAL CEREBRAL GLUCOSE-METABOLISM

In an attempt to elucidate the physiological basis of hypnosis, we inv estigated the changes of whole-brain and regional cerebral glucose met abolism, from a state of resting wakefulness to a hypnotized state wit h whole-body catalepsy, using positron emission tomography and the 2[F -18]fluorodeoxyglucose method in 15 highly hypnotizable adults. Neithe r the random order of study conditions nor any of the other experiment al factors had a measurable effect, and there was no statistically sig nificant global activation or metabolic depression. However, repeated measures analysis of variance revealed a statistically significant het erogeneity of symmetric regional responses: Mainly the occipital areas , including visual and paravisual cortex, became relatively deactivate d, while some metabolic recruitment was found in structures involved i n sensorimotor functions. The observed pattern of changes of regional cerebral activity corresponds with the shift of attention away from no rmal sensory input that hypnosis is known to produce.