Prospective time estimation and hypnotizability in a simulator design.

The present study of prospective time estimation examined the effects of hypnosis on short time intervals using a real-simulator design. The major hypothesis predicted a 2-way interaction between group (high hypnotizable, low hypnotizable, and simulator) and condition (waking and hypnotic) across all 4 time intervals (30, 60, 120, and 240 seconds). It was further hypothesized that on a "suggested" task (a measure of hypnotic depth), high hypnotizable Ss and simulators would not differ from each other but would differ from low hypnotizable Ss. 42 undergraduates were screened on both the Creative Imagination Scale (Wilson & Barber, 1977) and the Stanford Hypnotic Clinical Scale for Adults (Morgan & J. R. Hilgard, 1975, 1979) and assigned to 1 of 3 groups (high hypnotizable, low hypnotizable, simulator) based on combined hypnotizability scores. Ss verbally estimated time intervals of 30, 60, 120, and 240 seconds, 3 times each, both while in a waking and a hypnotic condition. Hypnotic depth was assessed once following each time interval. Partial support was found for the first hypothesis where, for both the 60- and 120-second intervals, high hypnotizable Ss increased their overestimation in the hypnotic condition. Low hypnotizable and simulator Ss showed no such increase. The second hypothesis, that high hypnotizable and simulator Ss would differ from low hypnotizables on the "suggested" task, was confirmed. The partial replication of previous research was examined in the context of choice of hypnotizability measure and reliability of time estimation.