Getting real about Semantic Illusions: Rethinking the functional role of the P600 in language comprehension

Abstract

In traditional theories of language comprehension, syntactic and semantic processing are inextricably linked. This assumption has been challenged by the 'Semantic Illusion Effect' found in studies using Event Related brain Potentials. Semantically anomalous sentences did not produce the expected increase in N400 amplitude but rather one in P600 amplitude. To explain these findings, complex models have been devised in which an independent semantic processing stream can arrive at a sentence interpretation that may differ from the interpretation prescribed by the syntactic structure of the sentence. We review five such multi-stream models and argue that they do not account for the full range of relevant results because they assume that the amplitude of the N400 indexes some form of semantic integration. Based on recent evidence we argue that N400 amplitude might reflect the retrieval of lexical information from memory. On this view, the absence of an N400-effect in Semantic Illusion sentences can be explained in terms of priming. Furthermore, we suggest that semantic integration, which has previously been linked to the N400 component, might be reflected in the P600 instead. When combined, these functional interpretations result in a single-stream account of language processing that can explain all of the Semantic Illusion data.

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

“…For example, Deacon and colleagues [10] and Kiefer [11] observed N400 priming effects with very short SOAs (< 70 ms) in a masked priming paradigm, suggesting that the underlying mechanism must have been ASA. Similarly, Brouwer and colleagues [12] suggest that the N400 is exclusively linked to lexical retrieval, while (post-lexical) semantic integration is supposed to be reflected by the P600 component. Moreover, as neuroimaging studies found consistent priming effects for the brain structure assumed to house the lexical semantic network (e.g., the posterior part of the middle temporal gyrus, pMTG), the influential review paper by Lau and colleagues [13] argued that retrievalrelated processes including ASA are likely to always contribute to N400 priming effects, irrespective of SOA duration.…”

“…Various recent articles (Lau et al, 2008;Brouwer et al, 2012) have revived the idea that only processes during word-retrieval (such as automatic spreading activation, ASA) are strongly supported, while post-lexical integrative processes are not. The present ERP study replicates a behavioral study by McKoon and Ratcliff (1995) who demonstrated that a prime-target pair such as finger -hand shows stronger priming when a majority of other pairs in the list share the analogous semantic relationship (here: part-whole), even at short stimulus onset asynchronies (250 ms).…”

A Neurocomputational Model of the N400 and the P600 in Language Processing

“…(2012) argued for a functional reinterpretation of the ERP components involved. First of all, in line with previous suggestions (Kutas & Federmeier, 2000; Lau, Phillips, & Poeppel, 2008; van Berkum, 2009), they propose that the N400 component reflects retrieval of lexical‐semantic information, rather than semantic integration or any other kind of compositional semantic processing.…”

Wait a second! delayed impact of argument roles on on-line verb prediction

“…First, some researchers adopted the integration view of the N400 (e.g., Hagoort et al, 2004) and have taken these results to indicate that comprehenders fail to detect implausibility in role-reversed sentences at least initially 3 ("Semantic Illusion" hypothesis, e.g., Bornkessel-Schlesewsky & Schlesewsky, 2008;Hoeks et al, 2004;Kim & Osterhout, 2005;Kolk et al, 2003;Kuperberg, 2007 On the other hand, some have focused on the N400's sensitivity to lexical semantic association and have attributed the lack of an N400 effect to argument role reversals to the fact that the verb tends to be strongly associated with its arguments in both canonical and rolereversal sentences (Brouwer, Fitz, & Hoeks, 2012). Under this view, argument role reversals should fail to modulate the N400 only when the verb is strongly associated with the arguments, and they should elicit an N400 effect when the verb is only weakly associated with the arguments.…”