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

People can establish whether a sentence is hypothetically true even if what it describes can never be literally true given the laws of the natural world. Two event-related potential (ERP) experiments examined electrophysiological responses to sentences about unrealistic counterfactual worlds that require people to construct novel conceptual combinations and infer their consequences as the sentence unfolds in time (e.g., “If dogs had gills…”). Experiment 1 established that without this premise, described consequences (e.g., “Dobermans would breathe under water …”) elicited larger N400 responses than real-world true sentences. Incorporation of the counterfactual premise in Experiment 2 generated similar N400 effects of propositional truth-value in counterfactual and real-world sentences, suggesting that the counterfactual context eliminated the interpretive problems posed by locally anomalous sentences. This result did not depend on cloze probability of the sentences. In contrast to earlier findings regarding online comprehension of logical operators and counterfactuals, these results show that ongoing processing can be directly impacted by propositional truth-value, even that of unrealistic counterfactuals.

Abstract

The animacy distinction is deeply rooted in the language faculty. A key example is differential object marking, the phenomenon where animate sentential objects receive specific marking. We used event-related potentials to examine the neural processing consequences of case-marking violations on animate and inanimate direct objects in Spanish. Inanimate objects with incorrect prepositional case marker ‘a’ (‘al suelo’) elicited a P600 effect compared to unmarked objects, consistent with previous literature. However, animate objects without the required prepositional case marker (‘el obispo’) only elicited an N400 effect compared to marked objects. This novel finding, an exclusive N400 modulation by a straightforward grammatical rule violation, does not follow from extant neurocognitive models of sentence processing, and mirrors unexpected “semantic P600” effects for thematically problematic sentences. These results may reflect animacy asymmetry in competition for argument prominence: following the article, thematic interpretation difficulties are elicited only by unexpectedly animate objects.

Abstract

In linguistic theories of how sentences encode meaning, a distinction is often made between the context-free rule-based combination of lexical–semantic features of the words within a sentence (‘‘semantics’’), and the contributions made by wider context (‘‘pragmatics’’). In psycholinguistics, this distinction has led to the view that listeners initially compute a local, context-independent meaning of a phrase or sentence before relating it to the wider context. An important aspect of such a two-step perspective on interpretation is that local semantics cannot initially be overruled by global contextual factors. In two spoken-language event-related potential experiments, we tested the viability of this claim by examining whether discourse context can overrule the impact of the core lexical–semantic feature animacy, considered to be an innate organizing principle of cognition. Two-step models of interpretation predict that verb–object animacy violations, as in ‘‘The girl comforted the clock,’’ will always perturb the unfolding interpretation process, regardless of wider context. When presented in isolation, such anomalies indeed elicit a clear N400 effect, a sign of interpretive problems. However, when the anomalies were embedded in a supportive context (e.g., a girl talking to a clock about his depression), this N400 effect disappeared completely. Moreover, given a suitable discourse context (e.g., a story about an amorous peanut), animacyviolating predicates (‘‘the peanut was in love’’) were actually processed more easily than canonical predicates (‘‘the peanut was salted’’). Our findings reveal that discourse context can immediately overrule local lexical–semantic violations, and therefore suggest that language comprehension does not involve an initially context-free semantic analysis.

Abstract

Although we usually have no trouble finding the right antecedent for a pronoun, the co-reference relations between pronouns and antecedents in everyday language are often ‘formally’ ambiguous. But a pronoun is only really ambiguous if a reader or listener indeed perceives it to be ambiguous. Whether this is the case may depend on at least two factors: the language processing skills of an individual reader, and the contextual bias towards one particular referential interpretation. In the current study, we used event related brain potentials (ERPs) to explore how both these factors affect the resolution of referentially ambiguous pronouns. We compared ERPs elicited by formally ambiguous and non-ambiguous pronouns that were embedded in simple sentences (e.g., “Jennifer Lopez told Madonna that she had too much money.”). Individual differences in language processing skills were assessed with the Reading Span task, while the contextual bias of each sentence (up to the critical pronoun) had been assessed in a referential cloze pretest. In line with earlier research, ambiguous pronouns elicited a sustained, frontal negative shift relative to non-ambiguous pronouns at the group-level. The size of this effect was correlated with Reading Span score, as well as with contextual bias. These results suggest that whether a reader perceives a formally ambiguous pronoun to be ambiguous is subtly co-determined by both individual language processing skills and contextual bias.