Weakening of the Sense of Body Ownership in Schizophrenia: Implications for the Psychological Mechanism of Anxiety Reduction

Abstract

The main aim of the study discussed in the present paper was to explore the role of disturbances of bodily experience (of the sense of body ownership) in the regulation of a general emotional state. An attempt was made to verify the hypothesis that the autonomic emotional response (i.e. the objective state of stress) and the subjective sense of stress in schizophrenic subjects would be markedly weakened due to the Rubber Hand Illusion, whereas it was suggested that no such change would appear in the control group consisting of healthy subjects. In the 64 subjects who participated in the study (31 schizophrenic subjects and 33 subjects with no diagnosed mental condition), general emotional state was measured before and after the induction of the Rubber Hand Illusion, with the general emotional state understood as the objective state (electrodermal response) and the subjective state (the sense of stress or relaxation). Experimentally-induced change in the sense of body ownership appeared to be a factor regulating the subjective and the objective emotional states in all subjects, although the type of change differed significantly between the groups. In the schizophrenic group, the induction of the Rubber Hand Illusion substantially reduced the subjective and objective states of stress, whilst in the control group an intensified electrodermal response was observed (objective state of stress), with the subjective emotional state remaining unaltered.