Static posed and evoked facial expressions of emotions in schizophrenia

Impaired facial expressions of emotions have been described as characteristic symptoms of schizophrenia. Differences regarding individual facial muscle changes associated with specific emotions in posed and evoked expressions remain unclear. This study examined static facial expressions of emotions for evidence of flattened and inappropriate affect in persons with stable schizophrenia.

12 persons with stable schizophrenia and matched healthy controls underwent a standardized procedure for posed and evoked facial expressions of five universal emotions, including happy, sad, anger, fear, and disgust expressions, at three intensity levels. Subjects completed self-ratings of their emotion experience. Certified raters coded images of facial expressions for presence of action units (AUs) according to the Facial Action Coding System. Logistic regression analyses were used to examine differences in the presence of AUs and emotion experience ratings by diagnosis, condition and intensity of expression.

Patient and control groups experienced similar intensities of emotions, however, the difference between posed and evoked emotions was less pronounced in patients. Differences in expression of frequent and infrequent AUs support clinical observations of flattened and inappropriate affect in schizophrenia. Specific differences involve the Duchenne smile for happy expressions and decreased furrowed brows in all negative emotion expressions in schizophrenia.

While patterns of facial expressions were similar between groups, general and emotion specific differences support the concept of impaired facial expressions in schizophrenia. Expression of emotions in schizophrenia could not be explained by impaired experience. Future directions may include automated measurement, remediation of expressions and early detection of schizophrenia.