A comparison of stages of attention for social and nonsocial stimuli in schizophrenia: An ERP study

Social motivation disturbances have been long observed in people with schizophrenia, yet the underlying components that drive these impairments remain unclear. Social attention is one component of social motivation and involves stages of attentional orienting, alerting/sustained attention, and executive control. It is not known at which stage the breakdown in social attention occurs in schizophrenia. The present study examined the allocation of social versus nonsocial attention at multiple stages of processing using event related potential (ERP) components. Electroencephalography from 36 outpatients with schizophrenia and 20 healthy participants was recorded during a dot probe task while viewing social/nonsocial stimuli that assessed: (1) orienting (indexed by the N1pc), (2) sustained attention (Contingent Negative Variation, [CNV]), and (3) executive control of attention during target evaluation (P300). Additionally, we analyzed correlations between the ERPs and participants' reaction times (RT) to the targets. Schizophrenia participants oriented their attention equally to social and nonsocial stimuli (N1pc), showed greater sustained attention to social than nonsocial stimuli (i.e., larger CNV), and exerted greater executive control on social trials (i.e., larger P300) than nonsocial trials, similarly to healthy participants. However, schizophrenia participants showed diminished overall sustained attention (blunted CNV) during the task, compared with healthy participants. Furthermore, greater sustained attention (larger CNV) and greater executive control (larger P300) were associated with improved behavioral performance (faster RTs) for healthy participants, but not schizophrenia participants. Together, these findings suggest there is impaired sustained attention for both social and nonsocial stimuli in schizophrenia, and their attention may not correspond with their behavior.