Aim: 

To investigate whether the peculiar attentional and imagery abilities associated with susceptibility to hypnosis make locomotion in highly hypnotizable subjects (Highs) less dependent on sensory modulation than in individuals with low hypnotic susceptibility (Lows), and whether imagery elicits the same behavioral effects than real sensory alteration.

Methods: 

Highs and Lows were asked to go straight ahead with eyes closed and their head in different positions as well as during imagery of those head positions and during mental computation. In each condition subjects were classified as R-type or L-type according to their preferred direction of veering (out or 3 trials). The number of R/L type participants and their mean amplitude of veering in each condition as well as the changes across different conditions were studied.

Results: 

In basal conditions (head ahead), right veering occurred more often than left veering. A higher repeatibility of the veering direction was observed in Lows. Right-side head rotation was more effective than left-side rotation. Changes during head rotation were more pronounced in Lows and females. Imagery was more effective in Highs and the effect was not due to cognitive load because mental computation was associated with different directions of veering.

Conclusion: 

Results suggest a higher automaticity in locomotion and a greater similarity between the effects induced by real and imagined sensory modulation in Highs, which is in line with the hypothesis of hypnotisability related differences in sensorimotor integration.