Variations in the sense of agency during hypnotic responding : Insights from latent profile analysis

The primary phenomenological feature of a response to hypnotic suggestion is the perception that a person is not the author of their actions and experiences. This distortion in volition during hypnotic responding, known as the classic suggestion effect, has the potential to illuminate the neurocognitive mechanisms underlying hypnosis and inform broader models of agency. Here we sought to clarify inter-individual differences in the patterns of agency that participants experience during hypnosis. We applied latent profile analysis, a finite mixture modeling method for partitioning participants into homogeneous classes, to participants’ responses to a standardized behavioral measure of hypnotic suggestibility and an experiential measure of sense of agency during hypnotic responding. The best fitting model suggested that there were four discrete response patterns: a low suggestible class, two medium suggestible classes, and one highly suggestible class. The two medium suggestible classes displayed nearly equivalent patterns of behavioural hypnotic responding but diverged in their experience of agency during hypnotic responding: one class experienced greater involuntariness during responding whereas the other experienced greater effortlessness during responding. These results reinforce previous research highlighting differential patterns of hypnotic responding and complement work suggesting that there may be two or more phenomenologically distinct modes of hypnotic responding. They also have a number of implications for the measurement of hypnotic responding and for the use of low and medium suggestible individuals in experimental hypnosis research designs.