Publications

Abstract

n conversations, interlocutors concurrently perform two related processes: speech comprehension and speech planning. We investigated effects of speech planning on comprehension using EEG. Dutch speakers listened to sentences that ended with expected or unexpected target words. In addition, a picture was presented two seconds after target onset (Experiment 1) or 50 ms before target onset (Experiment 2). Participants’ task was to name the picture or to stay quiet depending on the picture category. In Experiment 1, we found a strong N400 effect in response to unexpected compared to expected target words. Importantly, this N400 effect was reduced in Experiment 2 compared to Experiment 1. Unexpectedly, the N400 effect was not smaller in the naming compared to categorization condition. This indicates that conceptual preparation or the decision whether to speak (taking place in both task conditions of Experiment 2) rather than processes specific to word planning interfere with comprehension.

Abstract

Prediction is often regarded as an integral aspect of incremental language comprehension, but little is known about the cognitive architectures and mechanisms that support it. We review studies showing that listeners and readers use all manner of contextual information to generate multifaceted predictions about upcoming input. The nature of these predictions may vary between individuals owing to differences in language experience, among other factors. We then turn to unresolved questions which may guide the search for the underlying mechanisms. (i) Is prediction essential to language processing or an optional strategy? (ii) Are predictions generated from within the language system or by domain-general processes? (iii) What is the relationship between prediction and memory? (iv) Does prediction in comprehension require simulation via the production system? We discuss promising directions for making progress in answering these questions and for developing a mechanistic understanding of prediction in language.

Abstract

People sometimes predict upcoming words during language comprehension, but debate remains on when and to what extent such predictions indeed occur. The rational adaptation hypothesis holds that predictions develop with expected utility: people predict more strongly when predictions are frequently confirmed (low prediction error) rather than disconfirmed. However, supporting evidence is mixed thus far and has only involved measuring responses to supposedly predicted nouns, not to preceding articles that may also be predicted. The current, large-sample (N = 200) ERP study on written discourse comprehension in Dutch therefore employs the well-known ‘pre-nominal prediction effect’: enhanced N400-like ERPs for articles that are unexpected given a likely upcoming noun’s gender (i.e., the neuter gender article ‘het’ when people expect the common gender noun phrase ‘de krant’, the newspaper) compared to expected articles. We investigated whether the pre-nominal prediction effect is larger when most of the presented stories contain predictable article-noun combinations (75% predictable, 25% unpredictable) compared to when most stories contain unpredictable combinations (25% predictable, 75% unpredictable). Our results show the pre-nominal prediction effect in both contexts, with little evidence to suggest that this effect depended on the percentage of predictable combinations. Moreover, the little evidence suggesting such a dependence was primarily observed for unexpected, neuter-gender articles (‘het’), which is inconsistent with the rational adaptation hypothesis. In line with recent demonstrations (Nieuwland, 2021a,b), our results suggest that linguistic prediction is less ‘rational’ or Bayes optimal than is often suggested.