Neurophysiological correlates of configural face processing in schizotypy.

BACKGROUND: Face processing impairment in schizophrenia appears to be underpinned by poor configural (as opposed to feature-based) processing; however, few studies have sought to characterize this impairment electrophysiologically. Given the sensitivity of event-related potentials to antipsychotic medications, and the potential for neurophysiological abnormalities to serve as vulnerability markers for schizophrenia, a handful of studies have investigated early visual P100 and face-selective N170 in "at risk" populations. However, this is the first known neurophysiological investigation of configural face processing in a non-clinical schizotypal sample. METHODS: Using stimuli designed to engage configural processing in face perception (upright and inverted Mooney and photographic faces), P100 and N170 components were recorded in healthy individuals characterized by high (N = 14) and low (N = 14) schizotypal traits according to the Oxford-Liverpool Inventory of Feelings and Experiences. RESULTS: High schizotypes showed significantly reduced N170 amplitudes to inverted photographic faces. Typical N170 latency and amplitude inversion effects (delayed and enhanced N170 to inverted relative to upright photographic faces, and enhanced amplitude to upright versus inverted Mooney faces), were demonstrated by low, but not high, schizotypes. No group differences were shown for P100 analyses. CONCLUSIONS: The findings suggest that neurophysiological deficits in processing facial configurations (N170) are apparent in schizotypy, while the early sensory processing (P100) of faces appears intact. This work adds to the mounting evidence for analogous neural processing anomalies at the healthy end of the psychosis continuum.

Investigating facial affect processing in psychosis: a study using the Comprehensive Affective Testing System.

Facial affect processing (FAP) deficits in schizophrenia (SZ) and bipolar disorder (BD) have been widely reported; although effect sizes vary across studies, and there are limited direct comparisons of the two groups. Further, there is debate as to the influence of both psychotic and mood symptoms on FAP. This study aimed to address these limitations by recruiting groups of psychosis patients with either a diagnosis of SZ or BD and comparing them to healthy controls (HC) on a well validated battery of four FAP subtests: affect discrimination, name affect, select affect and match affect. Overall, both groups performed more poorly than controls in terms of accuracy. In SZ, this was largely driven by impairments on three of the four subtests. The BD patients showed impaired performance specifically on the match affect subtest, a task that had a high cognitive load. FAP performance in the psychosis patients was correlated with severity of positive symptoms and mania. This study confirmed that FAP deficits are a consistent finding in SZ that occur independent of task specific methodology; whilst FAP deficits in BD are more subtle. Further work in this group is needed to replicate these results.

Investigating affective prosody in psychosis: a study using the Comprehensive Affective Testing System.

Affective prosody is substantially impaired in schizophrenia, yet little is known about affective prosody in bipolar disorder (BD). The aim of this study was to examine affective prosody performance in schizophrenia, schizoaffective disorder and BD on a newly released standardised assessment to further our understanding of BD performance. Fifty-four schizophrenia, 11 schizoaffective and 43 BD patients were compared with 112 healthy controls (HC) on four affective prosody subtests of the Comprehensive Affective Testing System (CATS). Schizophrenia patients showed a 10% reduction in accuracy on two subtests compared to HC. BD showed a trend for performance intermediary to schizophrenia and HC; and schizoaffective patients performed more like HC on these four affective prosody measures. Severity of current auditory hallucination, across all patients, was related to task performance on three of the measures. These data confirm that schizophrenia and BD have reduced affective prosody performance, with deficits in BD being less pronounced than schizophrenia. The schizoaffective results in this study should be interpreted with caution due to small sample size.