Impaired anticipatory event-related potentials in schizophrenia

Deficits in anticipation are implicated across a variety of cognitive and emotional processes in schizophrenia. Although diminished anticipatory event-related potentials (ERPs) have been detected during tasks requiring motor response preparation in schizophrenia, no prior ERP study has examined non-motor-related anticipatory processes or used motivationally engaging stimuli. Thirty-four schizophrenia outpatients and 36 healthy controls completed a cued, reaction-time contingent picture viewing task to assess two types of anticipatory ERPs, one involving motor response preparation (Contingent Negative Variation [CNV]) and one not involving motor preparation (Stimulus Preceding Negativity [SPN]). The ERP paradigm included emotional and non-emotional pictures, and participants also completed trait anhedonia questionnaires. Patients and controls demonstrated similar patterns of reaction time and self-reported emotional responses to the pictures. However, patients demonstrated generally lower CNV and SPN across pleasant, neutral, and unpleasant picture conditions. Patients also reported lower anticipatory pleasure than controls on a trait questionnaire. Schizophrenia patients demonstrate diminished motor- and non-motor-related anticipatory processing, which may have wide-ranging adverse functional consequences.