ERP evidence for memory and predictive mechanisms in word-to-text integration

During reading, word-to-text integration (WTI) proceeds quickly and incrementally through both prediction and memory processes. We tested predictive and memory mechanisms with event-related potentials (ERPs) recorded on critical words that were across a sentence boundary from co-referential words that differed in dominant direction of lexical association. For comparison of text comprehension, participants performed meaning judgements on a matched set of word pairs. In both tasks, reduced N400 amplitudes were elicited over central scalp electrodes by words associated in either direction relative to task-specific baseline conditions. A temporal principal component analysis of the ERP data extracted a component reflecting this central N400. Additionally, for the text comprehension task early (N200) and late (parietal N400 and P600) discriminated between forward associated and backward associated conditions. The results demonstrate that, beyond N400 indicators of prediction, ERPs reflect the role of memory processes in WTI across sentences.