A functional anatomic study of emotion in schizophrenia

Using salient pictures with aversive (AV) and non-aversive (NA) content, we probed limbic-emotional function in schizophrenia, testing specific hypotheses that the amygdala would exhibit abnormal activity and a relationship with positive symptoms. Fourteen schizophrenic patients and 13 healthy comparison subjects viewed pictures during [¹⁵O] water positron emission tomography (PET). Both groups reported identical subjective experience of the aversive stimuli and both activated right insula (AV-NA). The schizophrenic group showed greater activation of the medial prefrontal cortex (MPFC) for the AV-NA comparison. Control subjects activated bilateral amygdaloid and orbitofrontal regions for NA relative to a blank condition (simple visual fixation, BL), whereas schizophrenic subjects only activated left orbitofrontal cortex. Activity in the left amygdala correlated with positive symptoms in the patients. Both groups activated visual cortex, and the schizophrenic subjects exhibited less modulation throughout visual cortex for NA-BL, as well as more focused deficits in the left fusiform and left mid-occipital gyrus for AV-NA, possibly related to decreased eye movements in the schizophrenic patients. Overall, the data are consistent with a general failure to process salient stimuli in schizophrenia, and the findings support the involvement of the amygdala in the positive symptoms of schizophrenia.