Subtypes of social perception deficits in schizophrenia. 
Persons with schizophrenia exhibit consistent deficits in emotion perception (recognizing the emotional expressions of others), but it is currently unclear if their performance represents a specific deficit in identifying emotions only or is a more generalized deficit across different perception tasks.  To address this question, it is important to compare emotion perception with face and general visual perception to assess the type of deficit present.  The equivocal nature of previous research may suggest the presence of subtypes with different levels and patterns of performance on social perception measures.  In this study, we administered measures of emotion, face, and general perception to a sample of 100 persons with schizophrenia.  These scores were then subjected to a cluster analysis to determine if different subtypes were present.  Two distinct subtypes were identified, and both subtypes scored lower than normal controls across all three measures of perception, suggesting the presence of a generalized performance deficit.  One subtype was characterized by mild to moderate impairment and the other showed more severe impairment.  The cluster solution was stable, and the subtypes also differed on other variables not used in the cluster analysis (external validation).  More specifically, persons in the mild to moderately impaired subtype reported fewer positive symptoms, and this subtype contained more persons with paranoid schizophrenia as compared to the more severely impaired subtype.  The implications of the results for the study of social cognition in schizophrenia are discussed.