Mental health week 2015: Schizophrenia and mirror system function

MAPrc student Dr Sophie Andrews supervised by Dr Kate Hoy, Professor Paul Fitzgerald, and Dr Richard Thomson recently authored a study which looked at patients with schizophrenia and whether their mirror neuron systems are impaired.

Dysfunctional mirror neuron systems have been proposed to contribute to the social cognitive deficits observed in schizophrenia. A few studies have explored mirror systems in schizophrenia using various techniques such as TMS (levels of motor resonance) or EEG (levels of mu suppression), with mixed results.

This study used a novel multimodal approach (eg: concurrent TMS and EEG) to further investigate mirror systems and social cognition in schizophrenia. Nineteen individuals with schizophrenia or schizoaffective disorder and 19 healthy controls participated.

The study found that the schizophrenia group showed significant deficits in facial affect recognition and higher level theory of mind, compared to healthy controls. A significant positive relationship was revealed between mu suppression and motor resonance for the overall sample, indicating concurrent validity of these measures. Levels of mu suppression and motor resonance were not significantly different between groups.

These findings indicate that in stable outpatients with schizophrenia, mirror system functioning is intact. Therefore, their social cognitive difficulties may be caused by alternative pathophysiology.

Reference (full study): Andrews SC, Enticott PG, Hoy KE, Thomson RH, Fitzgerald PB. No evidence for mirror system dysfunction in schizophrenia from a multimodal TMS/EEG study. Psychiatry Research 228:3,pp.431–440, 30 Aug 2015.