Abstract

Recent studies suggest an association between hypnotizability and superior frontal abilities (Crawford et al., 1998; Ray et al, 1998). Recent findings emphasize the role of Response Expectancy (RE) in predicting suggestibility (Braffman, & Kirsch, 1999; Council, 1999). This study had two aims: Firstly, to investigate cognitive correlates of hypnotizability and imaginativity. Secondly, to examine cognitive processes associated with RE and responsivity to different types of hypnotic suggestions. Eighty four participants completed RE questionnaire in two sessions, assessing behavioral and subjective RE, motivation, effort, and confidence, prior to suggestibility assessment on the HGSHS:A in both hypnosis and imagination conditions. In a third session, participants were administered imagery and absorption scales in addition to a battery of neuropsychological tests: Stroop, Digit Span, Self Ordered Pointing Test, Target Detection (D2), and Wisconsin Card Sorting Test. Expectancy was associated positively with imagery, absorption, and motivation in both conditions, and negatively with effort in hypnosis and with confidence in imagination. Predictors of hypnotizability were imaginative suggestibility, a faster RT on Stroop congruent and a slower RT on neutral trials. Predictors of imaginativity were: hypnotic suggestibility, behavioral RE, absorption, a slower RT on both Stroop congruent and incongruent, and a faster RT on neutral trials. Passing ideomotor suggestions was associated with imagery and absorption; and cognitive suggestions with verbal facilitation, interference, and weaker working memory. The role of STM in conscious experience is discussed in the context of a "Perceptual Control Model" of hypnosis based on the interactions of imagery, absorption, verbal facilitation and dissociation.