Effects of prediction and contextual support on lexical processing: Prediction takes precedence

Abstract

Readers may use contextual information to anticipate and pre-activate specific lexical items during reading. However, prior studies have not clearly dissociated the effects of accurate lexical prediction from other forms of contextual facilitation such as plausibility or semantic priming. In this study, we measured electrophysiological responses to predicted and unpredicted target words in passages providing varying levels of contextual support. This method was used to isolate the neural effects of prediction from other potential contextual influences on lexical processing. While both prediction and discourse context influenced ERP amplitudes within the time range of the N400, the effects of prediction occurred much more rapidly, preceding contextual facilitation by approximately 100ms. In addition, a frontal, post-N400 positivity (PNP) was modulated by both prediction accuracy and the overall plausibility of the preceding passage. These results suggest a unique temporal primacy for prediction in facilitating lexical access. They also suggest that the frontal PNP may index the costs of revising discourse representations following an incorrect lexical prediction.

The priming of priming: Evidence that the N400 reflects context-dependent post-retrieval word integration in working memory

“…As these processes were post-lexical (and took place in WM), the onset of this priming effect was delayed compared to ASA and reduced the N400 only after 400 ms. This might suggest that early N400 priming effects may be generally due to lexical pre-activation mechanisms (such as ASA and prediction) whereas later N400 effects after 400 ms are at least partly influenced by post-lexical integration (see [26] for a related notion of staged N400 effects). The observation that both N400 priming effects (in LTM and WM) lasted beyond 500 ms in our study (and many other N400 studies, e.g., [7,27]) is likely related to the specific task.…”

“…The earliest priming effect after target word onset affects both the more frontal N250 (formal phonological or orthographic priming; [7,26,27]) and the centro-parietal N400. Arguably, prediction-based priming requires a sufficiently long SOA between prime and target (600 ms in Lau et al [7]; but see Supplementary Materials).…”

Basic composition and enriched integration in idiom processing: An EEG study.

“…Table 5). In fact, ANOVAs revealed only one To better analyze the differences between conditions, we analyzed a subset of Frontal electrodes (FP1FP2,AF3,AF4,F3,Fz,F4,FC1,FC2) on which a Frontal PNP has been previously reported (e.g., Brothers et al, 2015;Thornhill & Van Petten, 2012 …”

“…A larger PNP for unexpected than for expected targets was observed; interestingly, the more implausible the sentences were, the larger were the positivities. These PNPs would reflect "meta-linguistic evaluation" processes (Molinaro et al, 2012) and/or "elaborate revisions or inferences" serving semantic integration processes (Brothers et al, 2015).…”

“…The more unnatural the sentences were, the larger was the positivity. Brothers, Swaab and Traxler (2015) directly tested the impact of misprediction on the PNP asking participants to explicitly judge whether the sentence-final words matched or not their prediction. The waveforms associated with expected vs. unexpected completions were then separately analysed.…”