Abstract:
Greater hypnotic susceptibility has been shown to correlate with faster reaction time in tasks with low stimulus response compatibility. We investigated the effect of hypnotic susceptibility on the speed of information processing in humans using a precued simple (SRT) and choice (CRT) reaction time experiment. Eighteen right handed participants (7 male), 19-31 y, assessed for hypnotic susceptibility (Stanford Hypnotic Susceptibility Scale Form C - SHSSC) were tested under hypnotised and non-hypnotised conditions performing a key-press task using their right or left index finger in response to a visual stimulus. Key-press forces and electromyographic (EMG) data were captured, from which premotor time, reaction time, motor time and movement time were measured. SHSSC scores revealed 9 “low” and 9 “high” susceptible participants. Between-group analysis of “high” vs “low” showed no difference in any of the measures. Within-group analysis showed that motor time was slower in hypnotised conditions for both the SRT (p=0.007) and CRT (p=0.036) tasks, with no difference between the conditions in on other measures. The findings do not support either of two hypotheses previously proposed to explain between person variability in hypnotic susceptibility, namely differences in focused attention abilities and response set theory. The slower motor times observed in the hypnotised state may be due to the type of hypnotic induction used.
