Association and not semantic relationships elicit the N400 effect: electrophysiological evidence from an explicit language comprehension task.

Language comprehension studies have identified the N400, an event-related potential (ERP) correlate of the processing of meaning, modulation of which is typically assumed to reflect the activation of semantic information. However, N400 studies of conscious language processing have not clearly distinguished between meaning derived from a semantic relationship and meaning extracted through association. We independently manipulated the presence of associative and semantic relationships while examining the N400 effect. Participants were asked to read and remember visually presented word pairs that shared an association (traffic-jam), an association+semantic relationship (lemon-orange), a semantic relationship alone (cereal-bread), or were unrelated (beard-tower). Modulation of the N400 (relative to unrelated word pairs) was observed for association and association+semantic word pairs but not for those that only shared a semantic relationship.