Using Hypnotic Suggestion to Model Loss of Control and Awareness of Movements: An Exploratory fMRI Study

Quinton Deeley,Cristina Koppel,David A Oakley,Eamonn Walsh,Peter W Halligan,Mitul A Mehta,Vaughan Bell,Natasha M Maurits

doi:10.1371/journal.pone.0078324

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.

Highlights

The normal sense of being able to initiate and control movements is altered or lost in a variety of neuropsychiatric disorders [1]
There was a main effect of hypnosis: movement amplitude in the nhyp-vol condition was significantly greater than the movement amplitude in the hyp-vol condition; t(9)=2.55; p=0.031
The main findings were that: i. subjective ratings of control and awareness varied in accordance with the specific suggestions for loss of control and awareness when compared to voluntary movement following the induction of hypnosis; ii. loss of voluntary control of hand movement was associated with reduced connectivity between supplementary motor area (SMA) and components of the motor network involved in movement implementation; and Hemisphere coordinates a) nhyp-vol >

Summary

Introduction

The normal sense of being able to initiate and control movements is altered or lost in a variety of neuropsychiatric disorders [1]. Awareness is partially or fully lost in up to 50% of patients [3] As dissociative disorders these involve a “disruption of the usually integrated functions of consciousness, memory, identity or perception of the environment” [4] understood as “an involuntary response to emotional, physical, or social distress” [3]. Involuntary movements associated with narrowing or loss of awareness occur in culturallyinfluenced dissociative phenomena linked to spirit possession, mediumship, and shamanism, which have been widely reported across different cultures and periods of history [5,6,7,8,9]. Whilst involuntary movements with or without loss of awareness are found in a variety of neuropsychiatric syndromes and culturally influenced alterations in experience and behaviour, the cognitive and neural processes underpinning these phenomena remain largely unknown [1,3]

Results

Discussion

Conclusion