Hypnotizability-dependent accuracy in the reproduction of haptically explored paths

The study assessed differences between highly (Highs) and low hypnotizable (Lows) subjects in the blindfolded reproduction of paths connected at acute or obtuse angles. Reproduction attempts were made after path exploration performed by one finger, with or without concomitant cognitive activities (mental computation or imagery of exploring an angle larger than the explored one). The variables analyzed were: subjective experience (scores of the exploring effort, reproduction difficulty, perceived accuracy of reproduction, attention to mental computation and efficacy of imagery), exploration time, relative error in reproduction (under or overestimation) and the percentage of “successful” trials (absolute error <10°). The results showed that the subjective experience of exploration/reproduction and the exploration times are similar in Highs and Lows and that all subjects underestimate the explored angles and reproduce the acute angle more accurately than the obtuse one. Exploration of the acute angle concomitant with imagery of a larger one reduced its underestimation in both groups. Highs exhibited a larger number of successful trials after exploration of the obtuse angle, while Lows (males) decreased their relative error in the reproduction of the acute angle. In conclusion, in the more demanding condition of reproducing an obtuse angle, the Highs’ reproduction was more accurate and more independent of cognitive load than that of the Lows.