On strategies for identifying neurochemical correlates of hypnotic analgesia: A brief communication

A test was made of the general hypothesis that central cholinergic mechanisms underlie hypnotic analgesia. Ss were given the cold pressor pain test under waking and 3 drug conditions. 6 Ss who scored very high on the tailored Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C-T) or E.R. Hilgard, Crawford, Bowers, and Kihlstrom (1979) were given atropine, propantheline, and placebo in double-blind and counterbalanced conditions, to determine if atropine would disrupt hypnotic analgesia. The study was replicated using Ss who scored lower on SHSS:C-T. The results showed only a nonsignificant tendency for atropine to interfere with hypnotic analgesia in the most hypnotizable group of Ss, and for both atropine and propantheline similarly to disrupt hypnotic analgesia for Ss in the less highly hypnotizable group. Alternative strategies are described for identifying the neurotransmitter(s) involved in the trance state.