Please cite this article in press as: Lotze, N., et al. Meaningful physical changes mediate lexical–semantic integration: Top-down and form-based bottom-up information sources interact in the N400. Neuropsychologia (2011), doi:10.1016/j.neuropsychologia.2011.09.009 ARTICLE IN PRESS G Model NSY 4251 1–10 Neuropsychologia xxx (2011) xxx–xxx Contents lists available at SciVerse ScienceDirect Neuropsychologia jo u rn al hom epa ge : www.elsevier.com/locate/neuropsychologia Meaningful physical changes mediate lexical–semantic integration: Top-down and form-based bottom-up information sources interact in the N400 1 2 Netaya Lotze a,1 , Sarah Tune b,1 , Matthias Schlesewsky c , Ina Bornkessel-Schlesewsky b,* Q1 3 a Department of Germanic Linguistics, University of Hannover, Hannover, Germany 4 b Department of Germanic Linguistics, University of Marburg, Marburg, Germany 5 c Department of English and Linguistics, Johannes Gutenberg-University, Mainz, Germany 6 7 a r t i c l e i n f o 8 9 Article history: 10 Received 31 January 2011 11 Received in revised form 25 July 2011 12 Accepted 7 September 2011 13 Available online xxx 14 Keywords: 15 Language comprehension 16 Semantics 17 Lexicon 18 Physical deviance 19 Computer-mediated communication 20 N400 21 Late positivity 22 Bidirectional coding account 23 a b s t r a c t Models of how the human brain reconstructs an intended meaning from a linguistic input often draw upon the N400 event-related potential (ERP) component as evidence. Current accounts of the N400 emphasise either the role of contextually induced lexical preactivation of a critical word (Lau, Phillips, & Poeppel, 2008) or the ease of integration into the overall discourse context including a wide variety of influencing factors (Hagoort & van Berkum, 2007). The present ERP study challenges both types of accounts by demonstrating a contextually independent and purely form-based bottom-up influence on the N400: the N400 effect for implausible sentence-endings was attenuated when the critical sentence- final word was capitalised (following a lowercase sentence context). By contrast, no N400 modulation occurred when the critical word involved a change from uppercase (sentence context) to lowercase. Thus, the N400 was only affected by a change to uppercase letters, as is often employed in computer-mediated communication as a sign of emphasis. This result indicates that N400 amplitude is reduced for unexpected words when a bottom-up (orthographic) cue signals that the word is likely to be highly informative. The lexical–semantic N400 thereby reflects the degree to which the semantic informativity of a critical word matches expectations, as determined by an interplay between top-down and bottom-up information sources, including purely form-based bottom-up information. © 2011 Published by Elsevier Ltd. 1. Introduction 24 Language provides us, as humans, with an immensely power- 25 ful and expressive means of communication. We can use it not 26 only to convey facts about the world, and thereby states of affairs 27 which may already be familiar to the addressee, but also to talk 28 about events that have never taken place and never will. For exam- 29 ple, if one were to tell a friend that Martians have landed on the 30 banks of the Rhine, he/she will likely never have experienced such 31 an event, but would nevertheless understand what the utterance 32 means (though he/she might not believe it). In view of this vast 33 expressive potential of language, it is not surprising that the ques- 34 tion of how the brain reconstructs the intended meaning from a 35 linguistic input has received a lot of attention in the literature on 36 the neuroscience of language. 37 * Corresponding author at: Department of Germanic Linguistics, University of Marburg, Wilhelm-Roepke-Strasse 6A, 35032 Marburg, Germany. Tel.: +49 0 6421 2824675; fax: +49 0 6421 2824558. E-mail address: iboke@staff.uni-marburg.de (I. Bornkessel-Schlesewsky). 1 Contributed equally to this paper. One position that has come to be highly influential in this regard 38 has been described as a “one-step model of language interpreta- 39 tion” (Hagoort & van Berkum, 2007, p. 802). This model essentially 40 claims that all available information sources (e.g. syntax, seman- 41 tics, prosody, discourse context, world knowledge, etc.) are all 42 taken into account immediately and simultaneously in the brain’s 43 computation of meaning (Crain & Steedman, 1985; e.g. Hagoort & 44 van Berkum, 2007; MacDonald, Pearlmutter, & Seidenberg, 1994; 45 Trueswell & Tanenhaus, 1994). This means, for example, that a new 46 word that is encountered in a particular sentence and discourse 47 context is not first integrated into the meaning of the sentence and, 48 only in a second stage, related to the broader discourse. Evidence 49 for the one-stage view has primarily been based on the N400 event- 50 related brain potential (ERP), an electrophysiological response that 51 has been known to be sensitive to meaning ever since it was first 52 reported by Kutas and Hillyard (1980) for semantically anomalous 53 (He spread the warm bread with socks) or unexpected (He took a 54 sip from the waterfall) continuations. Specifically, a range of recent 55 studies has demonstrated that the N400 is influenced by a number 56 of diverse factors such as discourse context (Van Berkum, Brown, 57 Hagoort, & Zwitserlood, 2003), world knowledge (Hagoort, Hald, 58 Bastiaansen, & Petersson, 2004) and even the identity of the speaker 59 0028-3932/$ – see front matter © 2011 Published by Elsevier Ltd. doi:10.1016/j.neuropsychologia.2011.09.009