ERPs and domain specificity: Beating a straw horse

We discuss the import, validity and implications of the identity thesis: the idea that the P600 component of the scalp recorded event-related brain potential is identical with the P3b, a domain-general component elicited by improbable task-relevant events. We point to data reported in Coulson, King and Kutas (1998), as well as more recently published findings, which suggest that the P600 component is sensitive to domain-general factors of probability, salience and task relevance. Exploring the epistemological complexities of the issue, we suggest what the identity thesis does and does not imply about the existence of a modular parser.