Biological motion processing in schizophrenia - Systematic review and meta-analysis.

CONTEXT: Patients with schizophrenia show impairments in processing of biological motion. This is especially important since deficits in domains of social cognition has been associated with functional outcome and everyday functioning in this population.

OBJECTIVES: We conducted a systematic review and meta-analysis of studies which have used point-light displays to present whole-body motion to patients with schizophrenia and healthy controls, to evaluate the magnitude of differences between these groups in biological motion processing.

METHOD: Firstly, relevant publications were identified by a systematic search of Google Scholar and PubMed databases. Secondly, we excluded non-relevant studies for the meta-analysis according to our exclusion criteria. Effect sizes were expressed as standardized mean difference (SMD).

RESULTS: 15 papers reporting results of 14 different experiments with 571 patients and 482 controls were included in the meta-analysis. The results for the general biological motion perception analysis revealed that patients with schizophrenia (compared with healthy controls) present reduced biological motion processing capacity with the effect size (SMD) of 0.66 (95% CI, -0.79 to -0.54; p<0.001). The results for the specific biological motion-based tasks were also statistically significant with SMD of 0.72 for Basic Biological Motion task (95% CI: -0.94 to -0.51; p<0.001) and SMD of 0.61 for Emotion in Biological Motion task, (95% CI: -0.79 to -0.43; p<0.001) respectively.

CONCLUSION: The findings from our meta-analysis highlight abnormalities in general and specific domains of biological motion perception in schizophrenia patients as compared with healthy controls.