Chapter 4 Impaired recognition and expression of emotional prosody in schizophrenia: review and meta-analysis*

Background Deficits in emotion processing may be one of most pervasive disturbances in schizophrenia that may contribute to social isolation. In this report, we focus on vocal emotion processing. This function bears upon two corner stones of social func-tioning, language and emotion, which have both been found to be impaired in schizo-phrenia. Methods We used meta-analysis to integrate findings of studies published between 1980 and June 2007 on perception of emotional prosody in schizophrenia. Seventeen studies provided sufficient information to be included. A mean weighted effect size was computed in the random effects model. Publication bias was tested using funnel plots and fail-safe number of studies. Seven studies were included in an analysis on the expression (i.e. production) of emotional prosody in schizophrenia. Results A significant and stable mean weighted effect size was found for the percep-tion of emotional prosody, d =-1.24, 95 % CI =-1.55 to- 0.93. The effect was also found in the early stages of the illness. Expression of emotional prosody was also sig-nificantly impaired, d=-1.11, 95 % CI =- 1.78 to- 0.43. Conclusions Results indicate that individuals with schizophrenia are impaired in the perception and expression of emotional prosody, with a large effect size. As a growing body of evidence shows that impaired social cognition in schizophrenia may be an important predictor of social out-come, training programs that aim at the recognition of emotional prosody should be developed