title: Prism Adaptation in hypnotically limb-anesthetized subjects: more disconfirming data.
abstract: Two experiments assessed the effect of hypnotically suggested arm anesthesia on adaptation to displacing prisms. In Study 1, 30 highly susceptible subjects adapted to prisms by pointing at a visual target for 2 min. with their hypnotically anesthetized dominant arm. Suggestion and hypnosis were then "lifted," and subjects were randomly assigned to three groups: subjects in one group were asked to move the hand slowly during the posttest (slow motion); those in a second group were told that hypnotic anesthesia would enable them to overcome displacement aftereffects (hypothesis informed); the remaining subjects (controls) were given no special instructions. During posttesting, all groups showed a significant displacement aftereffect, with no differences occurring between groups. Study 2 followed the same procedure except that during adaptation the usual target was removed and subjects pointed towards a homogeneous backboard. 20 highly susceptible subjects were assigned to an hypothesis-informed or control group immediately before posttesting. All subjects showed a significant displacement aftereffect. Both studies provide further evidence that hypnotic suggestions do not influence automatic perceptual processes. The results of Exp. 2 contradict the suggestion that hypnotic limb anesthesia eliminates the displacement aftereffect when the target is removed during adaptation trials.
mesh_terms: D005366:Figural Aftereffect; D006801:Humans; D006990:Hypnosis / Q000379:methods*; D010469:Perceptual Distortion; D011597:Psychomotor Performance; D011930:Reaction Time; D012718:Set, Psychology; D013404:Suggestion