Apathy, defined as a quantitative reduction of voluntary, goal-directed behaviours (GDB), is a core component of negative symptoms. It has been suggested that the physiopathology of apathy is not a single entity but may be multiple, depending on which specific process or macrofunction is disrupted during completion of GDB. In line with this notion, Levy and Dubois proposed dividing apathic syndromes into three subtypes of disrupted processing: 'a-motivation', 'cognitive inertia', and 'uncoupling'. In schizophrenia, apathy has been associated with executive dysfunction, functional impairment and poor outcome. However, the neurobiological underpinnings of apathy in schizophrenia are poorly understood.

Primary objective: confirm that chronic schizophrenic patients are apathic compared to healthy volunteers

Secondary objectives:

• investigate if apathy is related to a particular aspect of the disease (i.e. negative, positive symptomatology and/or deficit form)
• investigate if apathy correlates with executive dysfunction
• investigate if apathy is associated with a specific mechanism using an experimental task specially designed to investigate the different mechanism (i.e. 'a-motivation', 'cognitive inertia', and 'uncoupling')
• investigate if there is a volumetric abnormality affecting the executive system in apathic schizophrenic patients
• link these eventual volumetric abnormalities to prefrontal cortex-basal ganglia circuits according to a specific subtype of apathy in the apathic schizophrenic group

Inclusion Criteria (healthy volunteers):

• Male or Female aged 20 to 55 years old included
• Under French public assurance system

Exclusion Criteria (healthy volunteers):

• Personal history of neurological disorders
• Personal history of head injury
• Alcohol or substance abuse
• Under psychotropic drug
• Contraindication for MRI

Inclusion Criteria (schizophrenic patients):

• Male or Female aged 20 to 55 years old included
• Under French public assurance system
• diagnosis of schizophrenia according to the DSM-IV R criteria
• Duration of illness > 5 years
• clinical stability during the past 2 months (defined as no treatment modification or hospitalisation 2 months prior evaluation)

Exclusion Criteria (schizophrenic patients):

• Schizo-affective disorder
• Personal history of neurological disorders
• Personal history of head injury
• Alcohol or substance abuse
• Contraindication for MRI

schizophrenic patients:

• outpatients of the Corentin Celton psychiatric service
• inpatients of the Corentin Celton Day Hospital Unit

healthy volunteers: community