The hypothesis has been advanced by Gill and Brenman1 that a general reduction of sensory intake facilitates the attainment of an hypnotic state. Referring to the experiments on the effects of perceptual isolation, they state,
It seems clear that this experimental situation reproduced one of the features of the induction period—the restriction of sensory inflow—and results in some similar phenomena quite clearly indicative of a regressive movement.
While there are no studies dealing with the effect of perceptual isolation or sensory restriction on hypnotizability per se, there are several studies which indicate that these conditions increase suggestibility.2-4 The purpose of the present experiment was to test the Gill-Brenman hypothesis by attempting to hypnotize, following sensory restriction, individuals who had previously been found to be refractory to hypnosis.
Subjects and Procedure
The subjects were 3 sophomore student nurses who had successfully overcome a challenge of