Is avolition in schizophrenia associated with a deficit of dorsal caudate activity? A functional magnetic resonance imaging study during reward anticipation and feedback.

A Mucci,U Volpe,S Frangou,S Galderisi,M Salvatore,M Maj,A Prinster,P Bucci,D Dima,A Soricelli

doi:10.1017/s0033291714002943

Abstract

The neurobiological underpinnings of avolition in schizophrenia remain unclear. Most brain imaging research has focused on reward prediction deficit and on ventral striatum dysfunction, but findings are not consistent. In the light of accumulating evidence that both ventral striatum and dorsal caudate play a key role in motivation, we investigated ventral striatum and dorsal caudate activation during processing of reward or loss in patients with schizophrenia. We used functional magnetic resonance imaging to study brain activation during a Monetary Incentive Delay task in patients with schizophrenia, treated with second-generation antipsychotics only, and in healthy controls (HC). We also assessed the relationships of ventral striatum and dorsal caudate activation with measures of hedonic experience and motivation. The whole patient group had lower motivation but comparable hedonic experience and striatal activation than HC. Patients with high avolition scores showed lower dorsal caudate activation than both HC and patients with low avolition scores. A lower dorsal caudate activation was also observed in patients with deficit schizophrenia compared to HC and patients with non-deficit schizophrenia. Dorsal caudate activity during reward anticipation was significantly associated with avolition, but not with anhedonia in the patient group. These findings suggest that avolition in schizophrenia is linked to dorsal caudate hypoactivation.

Highlights

Avolition, i.e. a deficit of motivation, is highly prevalent in schizophrenia, being regarded as a key aspect of the negative syndrome (Kirkpatrick et al 2006; Foussias et al 2009; Strauss et al 2013a)
A lower dorsal caudate activation was observed in patients with deficit schizophrenia compared to healthy controls (HC) and patients with non-deficit schizophrenia
Dorsal caudate activity during reward anticipation was significantly associated with avolition, but not with anhedonia in the patient group

Summary

Introduction

I.e. a deficit of motivation, is highly prevalent in schizophrenia, being regarded as a key aspect of the negative syndrome (Kirkpatrick et al 2006; Foussias et al 2009; Strauss et al 2013a). Studies in healthy individuals have shown that a brain network including the ventral striatum, orbitofrontal cortex (OFC), insula, and medial prefrontal cortex (mPFC) is involved in some aspects of motivation, such as liking, reward anticipation, reward valuation, and representation of stimulus-reward associations, while a circuit including the dorsal caudate and. In the light of accumulating evidence that both ventral striatum and dorsal caudate play a key role in motivation, we investigated ventral striatum and dorsal caudate activation during processing of reward or loss in patients with schizophrenia

Methods

Results

Conclusion