Impairment of perception and recognition of faces, mimic expression and gestures in schizophrenic patients.

Abstract

The perception and recognition of faces, mimic expression and gestures were investigated in normal subjects and schizophrenic patients by means of a movie test described in a previous report (Berndl et al. 1986). The error scores were compared with results from a semi-quantitative evaluation of psychopathological symptoms and with some data from the case histories. The overall error scores found in the three groups of schizophrenic patients (paranoic, hebephrenic, schizo-affective) were significantly increased (7-fold) over those of normals. No significant difference in the distribution of the error scores in the three different patient groups was found. In 10 different sub-tests following the movie the deficiencies found in the schizophrenic patients were analysed in detail. The error score for the averbal test was on average higher in paranoic patients than in the two other groups of patients, while the opposite was true for the error scores found in the verbal tests. Age and sex had some impact on the test results. In normals, female subjects were somewhat better than male. In schizophrenic patients the reverse was true. Thus female patients were more affected by the disease than male patients with respect to the task performance. The correlation between duration of the disease and error score was small; less than 10% of the error scores could be attributed to factors related to the duration of illness. Evaluation of psychopathological symptoms indicated that the stronger the schizophrenic defect, the higher the error score, but again this relationship was responsible for not more than 10% of the errors. The estimated degree of acute psychosis and overall sum of psychopathological abnormalities as scored in a semi-quantitative exploration did not correlate with the error score, but with each other. Similarly, treatment with psychopharmaceuticals, previous misuse of drugs or of alcohol had practically no effect on the outcome of the test data. The analysis of performance and test data of schizophrenic patients indicated that our findings are most likely not due to a "non-specific" impairment of cognitive function in schizophrenia, but point to a fairly selective defect in elementary cognitive visual functions necessary for averbal social communication. Some possible explanations of the data are discussed in relation to neuropsychological and neurophysiological findings on "face-specific" cortical areas located in the primate temporal lobe.