New paper sheds light on anomalous bodily experiences in non-clinical hallucinators

Posted on Wednesday 4th June 2014

A new paper published in the Journal of Experimental Psychology: Human Perception and Performance examined whether individuals predisposed to anomalous bodily experiences would be more or less susceptible to the induction of the rubber-hand illusion. 

Participants took part in a rubber-hand illusion experiment, where the illusion that a fake rubber hand is part of the observer’s body is induced. Objective biophysical (psychophysiological) measures of emotional reactivity of the illusion were taken. 

The research, headed and conducted by Dr Jason Braithwaite, showed for the first time that non-clinical hallucinators were, counter intuitively, more resistant to the induction of the illusion relative to control participants. 

Individuals predisposed to anomalous body experiences actually took around 40 seconds longer to explicitly declare the presence of the illusion.  In addition, those predisposed to hallucinatory anomalous body experiences displayed distinct patterns in their emotional reactivity profiles during the illusion induction phase – with two new indicators being identified. 

This study revealed new and important differences in multi-sensory integration between those who were predisposed to anomalous experiences and control participants. It was suggested that this impairment might reflect a “dysconnection” between lower and higher cortical representations of the body-image which in turn generates an impairment in the temporal integration of multi-sensory information for those prone to anomalous bodily experiences. 

These findings have wide reaching implications for a range of inter-disciplinary fields including Clinical psychology, Neuropsychiatry, Abnormal psychology, research on the positive symptoms of Psychosis, Schizophrenia, as well as illuminating neuroscientific theories of self-consciousness and aberrant bodily experiences.     

Reference

Braithwaite, J.J., Broglia, E., & Watson, D.G (2014).  Autonomic emotional responses to the induction of the rubber-hand illusion in those that report anomalous bodily experiences: Evidence for specific psychophysiological components associated with illusory body representations.  Journal of Experimental Psychology: Human Perception & Performance, 40(3), 1131-1145.  doi: 10.1037/a0036077