Abnormalities of Event-Related Potential Components in Schizophrenia

Schizophrenia is a disabling psychotic illness that has been associated with alterations in synaptic connectivity and neurotransmission. Since event-related potential (ERP) components are typically generated by the summation of postsynaptic potentials produced by neural populations, these measures are well suited to assess such pathophysiological alterations. This chapter reviews the utility of ERP components in the investigation of the cognitive and neural mechanisms affected by schizophrenia. It focuses on five components: mismatch negativity (MMN), P50 measures of sensory gating, N100 and P300 in the oddball discrimination paradigms, and the N400 component elicited during language processing. These components test key cognitive systems affected by schizophrenia: sensory memory (MMN), sensory processing and inhibition (P50, N1), selective attention and working memory (P300), and semantic processing (N400). These components are discussed with respect to the following issues: (1) cognitive and neural systems indexed by the component, (2) abnormalities in schizophrenia, (3) sensitivity and specificity to schizophrenia, (4) clinical correlates, and (5) relationship to genetic variation. ERP components are well validated biomarkers for schizophrenia which have significant promise in the characterization of genomic and epigenomic factors, pharmacological response in humans and animal models, and the developmental and cognitive expression of the illness.