Facial and other non-verbal communicative behaviour in chronic schizophrenia

Facial behaviour may be an important determinant in clinical ratings of psychopathology. A standardized objective technique was used to quantify measures of facial behaviour in 21 chronic schizophrenic subjects, in comparison with control groups of depressed, demented and Parkinsonian subjects. Facial behaviours were counted and timed from video recordings of each subjects' face during a clinical interview. Separate measurement of behaviours were obtained while subjects were speaking and silent. For most variables, the amount of facial behaviour was significantly less in schizophrenic subjects than in control groups. The groups differed significantly on a number of measures, but schizophrenics could not be reliably identified by a single facial behaviour variable. However, using a discriminant function analysis with measures for eye contact while speaking and silent, broad smiles and small smiles, discrimination between groups was good, with over 80% correctly classified as either schizophrenic, or not schizophrenic. These techniques may increase our understanding of psychopathological signs and the mechanisms that underly them.