Visual processing, social cognition and functional outcome in schizophrenia.

Visual processing deficits are well recognised in schizophrenia and have potentially important clinical implications. First, the pattern of deficits for different visual tasks may help understand the underlying pathophysiology of the visual dysfunction. Second, several studies report deficits correlating with functional outcomes, suggesting that outcome improvement is possible through visual remediation strategies. We investigated these issues in a group of 64 schizophrenia patients and matched controls with a battery of visual tasks targeting different points along the visual pathways and by examining direct and indirect relationships (via a potential mediator) of such deficits to functional outcome. The schizophrenia group was significantly worse on the visual tasks overall, with the deficit constant for low- and high-level processing. Zero-order correlations suggested minimal association between vision and outcome, however, correlations between three visual tasks and 'social perceptual' ability were found which in turn correlated with functional outcome; path analysis confirmed a significant but small and indirect effect of 'biological motion' processing ability on functional outcome mediated by 'social perception'. In conclusion, the pathophysiology of visual dysfunction affects low- and high-level visual areas similarly and the relationship between deficits and outcome is small and indirect.