Comparison of the Effects of Aripiprazole and Risperidone on the Pattern of Brain Activation in Schizophrenic Patients

This study is: interventional, comparative, open label, multi center, without experimental treatment. Main objective: To evaluate the effect of aripiprazole and risperidone on brain activation during an emotional task of matching patients with schizophrenia, and in reference to control subjects. Secondary Objective: Comparison of emotional subjective and physiological perception in patients with schizophrenia in relation with their treatment. Comparison of brain activation in patients during the emotional induction task based on symptomatic dimensions, personality traits and performance on cognitive and attentional tests, and for insight capacity . Comparison of transcript level of candidate genes in blood mononuclear cells between the study groups and study the interactions between the observed differences in brain imaging and different levels of transcription of these genes.