Thirty Years and Counting: Finding Meaning in the N400 Component of the Event-Related Brain Potential (ERP)

We review the discovery, characterization, and evolving use of the N400, an event-related brain potential response linked to meaning processing. We describe the elicitation of N400s by an impressive range of stimulus types--including written, spoken, and signed words or pseudowords; drawings, photos, and videos of faces, objects, and actions; sounds; and mathematical symbols--and outline the sensitivity of N400 amplitude (as its latency is remarkably constant) to linguistic and nonlinguistic manipulations. We emphasize the effectiveness of the N400 as a dependent variable for examining almost every aspect of language processing and highlight its expanding use to probe semantic memory and to determine how the…