Body ownership across schizotypy dimensions: A rubber hand illusion experiment

Abstract

Bodily self disturbances are core features of schizophrenia. Body ownership, one component of the bodily self, can be assessed with the Rubber Hand Illusion (RHI), which is induced by a synchronous brushing of a visible fake hand and one's own occluded hand. Schizophrenia is associated with increased RHI strength and diminished body ownership. This study examined RHI in relation to schizotypy to extend our understanding of self-disturbances in the schizophrenia-spectrum. Ninety-seven college students completed the RHI task and self-report questionnaires. Regressions were used to assess the RHI strength in relation to the 3 schizotypy factors (positive, negative, disorganized). We also examined the correlations between self-reported bodily self disturbances and RHI strength. Positive schizotypy predicted a stronger subjective experience of the RHI, whereas negative schizotypy predicted weakened RHI susceptibility. Questionnaire measures of self-disturbances correlated with stronger RHI. In sum, we confirmed the link between positive schizotypy and the subjective experience of the RHI, which suggests a weakened sense of body ownership. Interestingly, we also found a relationship between negative schizotypy and reduced RHI, which implies strengthened body ownership. These results also underscore the complexity of the link between the phenomenological experience of bodily disturbances and the experimentally measured sense of body ownership. • Positive schizotypy predicts stronger RHI susceptibility. • Negative schizotypy predicts weaker RHI susceptibility. • Bodily self-disturbances correlate with RHI strength measured both objectively and subjectively.