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

Voluntary control and awareness of movement are central to selfhood and responsibility, yet can be lost in neuropsychiatric syndromes and dissociative states like spirit possession. Using suggestion and fMRI in 15 highly hypnotically suggestible subjects, loss of perceived control of movements was linked to reduced connectivity between the supplementary motor area (SMA) and motor regions. Reduced awareness of involuntary movements corresponded with less activation in parietal cortices and insula. These results suggest the sense of voluntary control may critically depend on SMA coupling with motor systems, offering a neural basis for narrowed awareness in pathological and culturally influenced dissociative phenomena.

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.