Hypnosis and its effects on left and right hemisphere activity.

Recent research suggests a relationship between hypnosis and the right cerebral hemisphere in man. With several major modifications in the 1978 study of Frumkin, Ripley, and Cox, the following hypothesis was investigated: Hypnosis creates a shift towards relatively greater left ear accuracy, suggesting greater participation of the right hemisphere during a trance. Two studies were undertaken with 36 right-handed male volunteers in each; 12 of low susceptibility to hypnosis, 12 of medium susceptibility, and 12 of high susceptibility. Study 1 investigated the affect hypnosis had on the processing of musical stimuli while Study 2 investigated its affects on verbal stimuli. Study 1 found that the more susceptible an individual was to hypnosis the greater the shift towards the left ear. Study 2 found no such relationship. Possible differences in stimulus characteristics which might have caused these different results were discussed.