Effect of word association on linguistic event-related potentials in moderately to mildly constraining sentences.

The processing of word associations in sentence context depends on several factors. EEG studies have shown that when the expectation of the upcoming word is high (high semantic constraint), the within-sentence word association plays a negligible role, whereas in the opposite case, when there is no expectation (as in pseudo-sentences), the role of word association becomes more pronounced. However, what happens when the expectations are not high (mild to moderate semantic constraint) is not yet clear. By adopting a cross-factorial design, crossing sentence congruity with within-sentence word association, our EEG recordings show that association comes into play during semantic processing of the word only when the sentence is meaningless. We also performed an exploratory source localization analysis of our EEG recordings to chart the brain regions putatively implicated in processing the said factors and showed its complementarity to EEG temporal analysis. This study furthers our knowledge on sentence processing and the brain networks involved in it.