Self-consciousness impairments in schizophrenia with and without first rank symptoms using the moving rubber hand illusion

Abstract

Introduction: The moving rubber hand illusion allows the evaluation both the sense of body ownership and agency using visuo-motor stimulations.

Methods: We used the moving rubber hand illusion in anatomic congruence with explicit measures to compare active asynchronous and passive synchronous movements in patients diagnosed with schizophrenia with first rank symptoms (FRS) (n = 31) versus without FRS (n = 25).

Results: Patients with FRS are characterized by a lack of agency in active asynchronous condition. The two groups had no sense of ownership in synchronous passive condition. Using a multivariate regression model, we found an association between agency and body ownership measures in the active asynchronous condition in two groups (OR: 1.825, p < 0.001). In the passive condition, this association was only present in the group with first rank symptoms (OR: 2.04, p < 0.001).

Conclusion: Temporal proximity and sensorimotor information are essential in the understanding of self-consciousness disorders in schizophrenia.

Keywords: First Rank Symptoms; Ownership; Rubber Hand Illusion; Schizophrenia; Self-consciousness; Sense of Agency.