Hypnotic hallucination alters evoked potentials.

Studied whether the amplitude of the visual EP is reduced during hypnotic hallucination in which the S is instructed to perceive visual stimuli as diminished in brightness or obstructed from view. The visual EP responses of 6 high- and 6 low-hypnotizable Ss (aged 18–33 yrs) and of 6 undergraduate controls were compared in 3 hypnotic conditions: stimulus enhancement, stimulus diminution, and stimulus elimination (obstructive hallucination). ANOVA revealed that high-hypnotizable Ss demonstrated significant suppression of the later components of the EP response (N? and P?) while experiencing obstructive hallucinations, indicating a change in information processing. This effect was significantly greater in the right, as compared to the left, occipital region. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)