Event-related potentials and event-related oscillations during identity and facial emotional processing in schizophrenia

Impairments in emotional recognition have been consistently reported in schizophrenic patients. The main aim of the present study was to evaluate time-sequenced responses in ERPs and event-related oscillations during emotional recognition of happiness and fear compared to facial identity recognition in schizophrenic patients (SCH) versus healthy controls (CON). Ten paranoid SCH and ten CON subjects performed three oddball paradigm tasks, evaluating face identity recognition and facial emotional recognition of happiness and fear. Event-related potentials and event-related theta and alpha oscillations were obtained for each task. N170 and P2 components appeared with higher amplitude in SCH than in CON at the occipital locations. An early prefrontally distributed P3a component was observed while doing the identity task with lower amplitude in SCH than in CON. Comparatively, P3b amplitude was lower in SCH than in CON over parietal leads in the identity and happiness tasks. Additionally, theta oscillations showed significantly lower RMS values in SCH between 250 and 500 ms post-stimuli in frontal and central regions. On the other hand, the grand-averaged alpha oscillations demonstrated higher RMS values in the occipital leads in SCH compared to CON and the opposite over the frontal regions. Results are interpreted in the framework of a functional disruption in the distributed neuronal networks involved both in facial identity and emotional recognition in schizophrenics as indexed by the brain oscillatory activity and related ERP components. (c) 2008 Elsevier B.V. All rights reserved.