Publications

Abstract

In this EEG study, we used pre-registered and exploratory ERP and time-frequency analyses to investigate the resolution of anaphoric and non-anaphoric noun phrases during discourse comprehension. Participants listened to story contexts that described two antecedents, and subsequently read a target sentence with a critical noun phrase that lexically matched one antecedent (‘old’), matched two antecedents (‘ambiguous’), partially matched one antecedent in terms of semantic features (‘partial-match’), or introduced another referent (non-anaphoric, ‘new’). After each target sentence, participants judged whether the noun referred back to an antecedent (i.e., an ‘old/new’ judgment), which was easiest for ambiguous nouns and hardest for partially matching nouns. The noun-elicited N400 ERP component demonstrated initial sensitivity to repetition and semantic overlap, corresponding to repetition and semantic priming effects, respectively. New and partially matching nouns both elicited a subsequent frontal positivity, which suggested that partially matching anaphors may have been processed as new nouns temporarily. ERPs in an even later time window and ERPs time-locked to sentence-final words suggested that new and partially matching nouns had different effects on comprehension, with partially matching nouns incurring additional processing costs up to the end of the sentence. In contrast to the ERP results, the time-frequency results primarily demonstrated sensitivity to noun repetition, and did not differentiate partially matching anaphors from new nouns. In sum, our results show the ERP and time-frequency effects of referent repetition during discourse comprehension, and demonstrate the potentially demanding nature of establishing the anaphoric meaning of a novel noun.

Abstract

Current theories of language comprehension posit that readers and listeners routinely try to predict the meaning but also the visual or sound form of upcoming words. Whereas
most neuroimaging studies on word rediction focus on the N400 ERP or its magnetic equivalent, various studies claim that word form prediction manifests itself in ‘early’, pre
N400 brain responses (e.g., ELAN, M100, P130, N1, P2, N200/PMN, N250). Modulations of these components are often taken as evidence that word form prediction impacts early sensory processes (the sensory hypothesis) or, alternatively, the initial stages of word recognition before word meaning is integrated with sentence context (the recognition hypothesis). Here, I
comprehensively review studies on sentence- or discourse-level language comprehension that report such effects of prediction on early brain responses. I conclude that the reported evidence for the sensory hypothesis or word recognition hypothesis is weak and inconsistent,
and highlight the urgent need for replication of previous findings. I discuss the implications and challenges to current theories of linguistic prediction and suggest avenues for future research.

Abstract

The literature suggests that individuals with autism spectrum disorders (ASD) are deficient in their Theory of Mind (ToM) abilities. They sometimes do not seem to appreciate that behaviour is motivated by underlying mental states. If this is true, then individuals with ASD should also be deficient when they use their ToM to represent and take part in dyadic interactions. In the current study we compared the performance of normally intelligent adolescents and adults with ASD to typically developing controls. In one task they heard a narrative about an interaction and then retold it. In a second task they played a communication game that required them to take into account another person's perspective. We found that when they described people's behaviour the ASD individuals used fewer mental terms in their story narration, suggesting a lower tendency to represent interactions in mentalistic terms. Surprisingly, ASD individuals and control participants showed the same level of performance in the communication game that required them to distinguish between their beliefs and the other's beliefs. Given that ASD individuals show no deficiency in using their ToM in real interaction, it is unlikely that they have a systematically deficient ToM.

Abstract

An endophenotype for attention deficit/hyperactivity disorder (AD/HD) is executive functioning. In the autism and developmental literature executive dysfunctions has also been linked to theory of mind (ToM) and pragmatic language use. The central question of this review is whether deficits in ToM and pragmatic language use are common in AD/HD. AD/HD seems to be associated with pragmatic deficits, but not with ToM deficits. In this review we address how this pattern of findings might facilitate the understanding of the commonalities and differences between executive functioning, ToM, and pragmatic abilities. Based on the reviewed studies we conclude that ToM is not likely to be a potential endophenotype for AD/HD, while it is too early to draw such a conclusion for pragmatic language use.

Abstract

In two event-related potential (ERP) experiments, we determined to what extent Grice’s maxim of informativeness as well as pragmatic ability contributes to the incremental build-up of sentence meaning, by examining the impact of underinformative versus informative scalar statements (e.g. “Some people have lungs/pets, and…”) on the N400 event-related potential (ERP), an electrophysiological index of semantic processing. In Experiment 1, only pragmatically skilled participants (as indexed by the Autism Quotient Communication subscale) showed a larger N400 to underinformative statements. In Experiment 2, this effect disappeared when the critical words were unfocused so that the local underinformativeness went unnoticed (e.g., “Some people have lungs that…”). Our results suggest that, while pragmatic scalar meaning can incrementally contribute to sentence comprehension, this contribution is dependent on contextual factors, whether these are derived from individual pragmatic abilities or the overall experimental context.

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.