Background: Patients with schizophrenia exhibit facial information processing deficits that likely contribute to their social dysfunction. Whether the deficits involve facial affect and/or identity processing or result from other cognitive abnormalities in schizophrenia remains controversial, and a brain dysfunction specifically related to them has never been reported. If such dysfunction existed, it should be consistently observed across groups of patients and during performance of different facial information processing tasks, independently of whether such tasks demand working memory (WM), semantic, or other cognitive processes. We hypothesized that the right lateral fusiform gyrus (rLFG), one of several human brain areas involved in facial information processing, would consistently show activation abnormalities during both facial affect and identity discrimination in schizophrenia.
Methods: We used functional magnetic resonance imaging to measure brain activation in two groups of six chronic, stable schizophrenic outpatients and two of six age- and gender-matched healthy controls. One group of patients and one of controls performed facial affect-with or without semantic processing-and identity discrimination tasks, and the other two groups WM tasks with facial expression cues and varying attentional demands.
Results: Patients from either group failed to activate the rLFG when compared to controls in any task. Other activation abnormalities were task-specific (i.e., seen only during performance of one set of tasks) and not consistently observed in both groups of patients, and thus could not be directly and solely linked to facial information discrimination.
Conclusions: These results indicate a specific rLFG dysfunction during early facial information--identity or affect--processing, independent from other cognitive deficits, in schizophrenia.