Using hypnotic suggestion to model loss of control and awareness of movements: an exploratory FMRI study.

Summary

Loss of perceived control over hand movements is linked to decreased connectivity between the supplementary motor area and motor regions, while reduced awareness of involuntary movements correlates with lower activation in specific brain areas. This study involved 15 highly hypnotically suggestible individuals and suggests that the sense of voluntary movement may rely on the functional coupling of the supplementary motor area with motor systems, offering insights into conditions that affect self-awareness and control.

Study at a glance

Abstract

The feeling of voluntary control and awareness of movement is fundamental to our notions of selfhood and responsibility for actions, yet can be lost in neuropsychiatric syndromes (e.g. delusions of control, non-epileptic seizures) and culturally influenced dissociative states (e.g. attributions of spirit possession). The brain processes involved remain poorly understood. We used suggestion and functional magnetic resonance imaging (fMRI) to investigate loss of control and awareness of right hand movements in 15 highly hypnotically suggestible subjects. Loss of perceived control of movements was associated with reduced connectivity between supplementary motor area (SMA) and motor regions. Reduced awareness of involuntary movements was associated with less activation in parietal cortices (BA 7, BA 40) and insula. Collectively these results suggest that the sense of voluntary control of movement may critically depend on the functional coupling of SMA with motor systems, and provide a potential neural basis for the narrowing of awareness reported in pathological and culturally influenced dissociative phenomena.