Cognitive Control Influences the Use of Meaning Relations during Spoken Sentence Comprehension

The aim of this study was to investigate individual differences in the influence of lexical association on word recognition during auditory sentence processing. Lexical associations among individual words (e.g. salt and pepper) represent one type of semantic information that is available during the processing of words in context. We predicted that individuals would vary in their sensitivity to this type of local context as a function of suppression ability and working-memory capacity. Lexical association was manipulated in auditory sentence contexts, and multiple regression analyses were employed to examine the relation between individuals' brain responses to meaning relations in sentences and measures of working-memory capacity, cognitive control and vocabulary. Lexical association influenced the processing of words that were embedded in sentences and also showed a great deal of individual variability. Specifically, suppression ability emerged as a significant predictor of sensitivity to lexical association, such that individuals who performed poorly on our measure of suppression ability (the Stroop task), compared to those who performed well, showed larger N400 effects of lexical association. (Contains 3 figures and 4 tables.)