Suggested visual hallucinations in and out of hypnosis.

We administered suggestions to see a gray-scale pattern as colored and a colored pattern in shades of gray to 30 high suggestible and eight low suggestible students. The suggestions were administered twice, once following the induction of hypnosis and once without an induction. Besides rating the degree of color they saw in the stimuli differently, participants also rated their states of consciousness as normal, relaxed, hypnotized, or deeply hypnotized. Reports of being hypnotized were limited to highly suggestible participants and only after the hypnotic induction had been administered. Reports of altered color perception were also limited to high suggestibles, but were roughly comparable regardless of whether hypnosis had been induced. These data indicate that suggestible individuals do not slip into a hypnotic state when given imaginative suggestions without the induction of hypnosis, but nevertheless report experiencing difficult suggestions for profound perceptual alterations that are pheonomenologically similar to what they report in hypnosis.

Conscious Cogn. 2009 Jun;18(2):494-9. Mazzoni G, Rotriquenz E, Carvalho C, Vannucci M, Roberts K, Kirsch I. University of Hull, Department of Psychology, Cottingham Road, Hull HU5 3EY, United Kingdom.