The influences of working memory updating on word association effects and thematic role assignment during sentence processing

The current study investigated how individual variability in working memory (WM) updating affects real-time processing of thematic role assignment and word association during sentence reading comprehension when ERPs were recorded. By adopting a factorial design, four types of sentences were formed by crossing word association and role assignment as independent variables. The results indicated that associated words evoked a smaller N400 effect but a larger P600 effect than unassociated words in the high WM group, whereas no word association effect was found in the low WM group. In contrast, role reversal elicited larger N400 effects for both groups. These results suggest that individual differences in WM updating influenced whether and how readers retrieved and integrated the associated word in whole sentences but did not influence the online assignment of thematic roles during sentence reading. Individuals with high WM updating, in contrast to those with low WM updating, were good at making use of word-associated information provided by the preceding context in current processing.