Cognitive control in high and low suggestible individuals.

Abstract

The current work aimed to investigate cognitive control use in high and low hypnotically suggestible individuals in the context of the Dual-Mechanisms of Control Framework (Braver, 2012), to determine whether the differences in suggestion response are explained by the type of cognitive control individuals employ. The first experimental chapter set out to compare effortful, proactive control use in both medium-high and low-medium suggestible individuals, both under suggestion and at baseline, using the word-blindness suggestion to modify Stroop task performance. An eye-tracker was used to measure pupil size as an indicator of effortful control use (Parris et al., 2021). The findings replicated the word blindness suggestion effect in the RT data but did not differ between medium-highs and low-mediums. Furthermore, contrary to Parris et al. no increase in effort was observed between the two groups in response to suggestion, indicating effort was not responsible for this effect. The second experimental chapter aimed to investigate cognitive control outside of the hypnotic context, to test control use as a predictor for suggestibility, involuntariness and effortlessness. The task consisted of three blocks of trials (List-Wise mostly incongruent, List-Wise mostly congruent and Item-Specific Proportion Congruency) in order to test proactive and reactive control use and their relationship to the three dependent variables. The regression analysis failed to show any relationship between control use and suggestibility, involuntariness or effortlessness.