Sep 27 2012
By Mark Cowen, Senior medwireNews Reporter
Individuals at risk for schizophrenia show significant deficits in facial affect recognition compared with mentally healthy individuals, researchers report.
Furthermore, among at-risk patients, an increased number of negative symptoms was associated with poorer performance on a facial affect recognition task.
Previous research has shown that patients with full-blown schizophrenia have significant problems recognizing facial expression of emotion.
The current findings suggest that "impairments in facial affect recognition precede the onset of the initial psychotic episode," say Wolfgang Wölwer (University of Düsseldorf, Germany) and colleagues.
The team recruited 37 individuals at risk for schizophrenia due to early signs of the disorder and 32 age- and gender-matched mentally healthy individuals.
For the facial affect recognition task, all participants were asked to view 30 facial photographs of expressed emotion and correct responses were recorded.
During the task, event-related potentials (ERPs) were recorded using electroencephalogram (EEG) to investigate electrophysiologic activity.
The researchers found that at-risk individuals had significantly fewer correct responses on the facial affect recognition task than controls, at a mean of 21.9 versus 24.9.
At-risk participants also had significantly reduced amplitudes in the ERP components P100, N170, and N250 compared with controls.
Among at-risk individuals, there was a trend toward an association between poorer facial affect recognition performance and more pronounced negative symptoms, but there was no correlation between facial affect recognition performance and general psychopathology or positive symptoms.
The team also found that prodromal signs, as assessed using the Early Recognition Inventory, negatively correlated with the amplitude of the N250 ERP component in individuals at risk for schizophrenia. Neither N170 nor P100 amplitudes were associated with ERI score.
Wölwer et al conclude in Schizophrenia Bulletin: "The reliable discrimination of emotional expressions in faces is essential for adequate social interaction. The results of the present study demonstrate that this ability is impaired in individuals at risk for schizophrenia, ie, before the onset of the manifest disorder.
"Furthermore, the fact that the EEG abnormalities we found in at-risk individuals in this study are qualitatively similar to those in schizophrenia patients identified in earlier studies suggests that the neural processes underlying facial affect recognition deficits might indeed be part of a basic neural dysfunction reflecting a vulnerability characteristic or an endophenotype of schizophrenia."
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