Publications

Abstract

Referential ambiguity arises whenever readers or listeners are unable to select a unique referent for a linguistic expression out of multiple candidates. In the current article, we review a series of neurocognitive experiments from our laboratory that examine the neural correlates of referential ambiguity, and that employ the brain signature of referential ambiguity to derive functional properties of the language comprehension system. The results of our experiments converge to show that referential ambiguity resolution involves making an inference to evaluate the referential candidates. These inferences only take place when both referential candidates are, at least initially, equally plausible antecedents. Whether comprehenders make these anaphoric inferences is strongly context dependent and co-determined by characteristics of the reader. In addition, readers appear to disregard referential ambiguity when the competing candidates are each semantically incoherent, suggesting that, under certain circumstances, semantic analysis can proceed even when referential analysis has not yielded a unique antecedent. Finally, results from a functional neuroimaging study suggest that whereas the neural systems that deal with referential ambiguity partially overlap with those that deal with referential failure, they show an inverse coupling with the neural systems associated with semantic processing, possibly reflecting the relative contributions of semantic and episodic processing to re-establish semantic and referential coherence, respectively.

Abstract

In this event-related brain potential (ERP) study, we examined how semantic and referential aspects of anaphoric noun phrase resolution interact during discourse comprehension. We used a full factorial design that crossed referential ambiguity with semantic incoherence. Ambiguous anaphors elicited a sustained negative shift (Nref effect), and incoherent anaphors elicited an N400 effect. Simultaneously ambiguous and incoherent anaphors elicited an ERP pattern resembling that of the incoherent anaphors. These results suggest that semantic incoherence can preclude readers from engaging in anaphoric inferencing. Furthermore, approximately half of our participants unexpectedly showed common late positive effects to the three types of problematic anaphors. We relate the latter finding to recent accounts of what the P600 might reflect, and to the role of individual differences therein.

Abstract

Our brains rapidly map incoming language onto what we hold to be true. Yet there are claims that such integration and verification processes are delayed in sentences containing negation words like not. However, studies have often confounded whether a statement is true and whether it is a natural thing to say during normal communication. In an event-related potential (ERP) experiment, we aimed to disentangle effects of truth value and pragmatic licensing on the comprehension of affirmative and negated real-world statements. As in affirmative sentences, false words elicited a larger N400 ERP than did true words in pragmatically licensed negated sentences (e.g., “In moderation, drinking red wine isn't bad/good…”), whereas true and false words elicited similar responses in unlicensed negated sentences (e.g., “A baby bunny's fur isn't very hard/soft…”). These results suggest that negation poses no principled obstacle for readers to immediately relate incoming words to what they hold to be true.