The effects of hypnotic suggestion on pain report.

Forty-five highly susceptible volunteers rated a series of shocks using 32 pain descriptors. Descriptors were given numerical values using magnitude estimation procedures. We assigned the subjects to one of three conditions, analgesia suggestion, relaxation suggestion, or no suggestion. All subjects were administered the shocks and the suggestion appropriate to the group, in both the waking and hypnotic state. The results support the existence of two dimensions of pain which are differentially responsive to suggestion. Hypnotic-analgesia suggestion altered subjects' perceptions of the intensity without changing their perceptions of the unpleasantness of the shocks. Hypnotic-relaxation suggestion reduced the unpleasantness but not the perceived intensity of the stimuli. These findings imply that research into hypnotic pain relief is more easily interpreted if pain is viewed as multidimensional in nature.