Typicality range deficit in schizophrenics' recognition of emotion in faces

Severity of thought disorder in schizophrenics was assessed by a task that involved recognition of joy and shame expression, with the expressions varied for typicality of the emotion category. Accuracy, typicality rating, and reaction time were measured in schizophrenic patients who were high or low on Whitaker's Index of Schizophrenic Thinking (WIST) and in depressive and normal controls. All groups had significant variation of typicality ratings for joy (normal typicality range), but the clinical groups had smaller typicality ranges for shame recognition and higher mean typicality ratings than did normals. High WIST schizophrenics were least accurate on low typical shame expressions. Results imply that, for shame recognition, schizophrenic and depressive groups used common categorization (no typicality variation in category members) rather than resemblance categorization.