Publications

Abstract

Linguistic predictions may be generated from and evaluated against a representation of events and referents described in the discourse. Compatible with this idea, recent work shows that predictions about novel noun phrases include their definiteness. In the current follow-up study, we ask whether people engage similar prediction-related processes for definite and indefinite referents. This question is relevant for linguistic theories that imply a processing difference between definite and indefinite noun phrases, typically because definiteness is thought to require a uniquely identifiable referent in the discourse. We addressed this question in an event-related potential (ERP) study (N = 48) with preregistration of data acquisition, preprocessing, and Bayesian analysis. Participants read Dutch mini-stories with a definite or indefinite novel noun phrase (e.g., “het/een huis,” the/a house), wherein (in)definiteness of the article was either expected or unexpected and the noun was always strongly expected. Unexpected articles elicited enhanced N400s, but unexpectedly indefinite articles also elicited a positive ERP effect at frontal channels compared to expectedly indefinite articles. We tentatively link this effect to an antiuniqueness violation, which may force people to introduce a new referent over and above the already anticipated one. Interestingly, expectedly definite nouns elicited larger N400s than unexpectedly definite nouns (replicating a previous surprising finding) and indefinite nouns. Although the exact nature of these noun effects remains unknown, expectedly definite nouns may have triggered the strongest semantic activation because they alone refer to specific and concrete referents. In sum, results from both the articles and nouns clearly demonstrate that definiteness marking has a rapid effect on processing, counter to recent claims regarding definiteness processing.

Abstract

Prediction-based theories of language comprehension assume that listeners predict both the meaning and phonological form of likely upcoming words. In alleged event-related potential (ERP) demonstrations of phonological prediction, prediction-mismatching words elicit a phonological mismatch negativity (PMN), a frontocentral negativity that precedes the centroparietal N400 component. However, classification and replicability of the PMN has proven controversial, with ongoing debate on whether the PMN is a distinct component or merely an early part of the N400. In this electroencephalography (EEG) study, we therefore attempted to replicate the PMN effect and its separability from the N400, using a participant sample size (N = 48) that was more than double that of previous studies. Participants listened to sentences containing either a predictable word or an unpredictable word with/without phonological overlap with the predictable word. Preregistered analyses revealed a widely distributed negative-going ERP in response to unpredictable words in both the early (150–250 ms) and the N400 (300–500 ms) time windows. Bayes factor analysis yielded moderate evidence against a different scalp distribution of the effects in the two time windows. Although our findings do not speak against phonological prediction during sentence comprehension, they do speak against the PMN effect specifically as a marker of phonological prediction mismatch. Instead of an PMN effect, our results demonstrate the early onset of the auditory N400 effect associated with unpredictable words. Our failure to replicate further highlights the risk associated with commonly employed data-contingent analyses (e.g., analyses involving time windows or electrodes that were selected based on visual inspection) and small sample sizes in the cognitive neuroscience of language.

Abstract

How does knowledge of real-world events shape our understanding of incoming language? Do temporal terms like “before” and “after” impact the online recruitment of real-world event knowledge? These questions were addressed in two ERP experiments, wherein participants read sentences that started with “before” or “after” and contained a critical word that rendered each sentence true or false (e.g., “Before/After the global economic crisis, securing a mortgage was easy/harder”). The critical words were matched on predictability, rated truth value, and semantic relatedness to the words in the sentence. Regardless of whether participants explicitly verified the sentences or not, false-after-sentences elicited larger N400s than true-after-sentences, consistent with the well-established finding that semantic retrieval of concepts is facilitated when they are consistent with real-world knowledge. However, although the truth judgments did not differ between before- and after-sentences, no such sentence N400 truth value effect occurred in before-sentences, whereas false-before-sentences elicited an enhanced subsequent positive ERPs. The temporal term “before” itself elicited more negative ERPs at central electrode channels than “after.” These patterns of results show that, irrespective of ultimate sentence truth value judgments, semantic retrieval of concepts is momentarily facilitated when they are consistent with the known event outcome compared to when they are not. However, this inappropriate facilitation incurs later processing costs as reflected in the subsequent positive ERP deflections. The results suggest that automatic activation of event knowledge can impede the incremental semantic processes required to establish sentence truth value.

Abstract

In general, language comprehension is surprisingly reliable. Listeners very rapidly extract meaning from the unfolding speech signal, on a word-by-word basis, and usually successfully. Research on ‘semantic illusions’ however suggests that under certain conditions, people fail to notice that the linguistic input simply doesn't make sense. In the current event-related brain potentials (ERP) study, we examined whether listeners would, under such conditions, spontaneously detect an anomaly in which a human character central to the story at hand (e.g., “a tourist”) was suddenly replaced by an inanimate object (e.g., “a suitcase”). Because this replacement introduced a very powerful coherence break, we expected listeners to immediately notice the anomaly and generate the standard ERP effect associated with incoherent language, the N400 effect. However, instead of the standard N400 effect, anomalous words elicited a positive ERP effect from about 500–600 ms onwards. The absence of an N400 effect suggests that subjects did not immediately notice the anomaly, and that for a few hundred milliseconds the comprehension system has converged on an apparently coherent but factually incorrect interpretation. The presence of the later ERP effect indicates that subjects were processing for comprehension and did ultimately detect the anomaly. Therefore, we take the absence of a regular N400 effect as the online manifestation of a temporary semantic illusion. Our results also show that even attentive listeners sometimes fail to notice a radical change in the nature of a story character, and therefore suggest a case of short-lived ‘semantic change deafness’ in language comprehension.