The P600 as a continuous index of integration effort
Aurnhammer,Christoph Delogu,Francesca Brouwer,Harm Crocker,Matthew W.
Aurnhammer,Christoph
Delogu,Francesca
Brouwer,Harm
Crocker,Matthew W.
Abstract
The integration of word meaning into an unfolding utterance representation is a core operation of incremental language comprehension. There is considerable debate, however, as to which component of the ERP signal— the N400 or the P600— directly reflects integrative processes, with far reaching consequences for the temporal organization and architecture of the comprehension system. Multi- stream models maintaining the N400 as integration crucially rely on the pres-ence of a semantically attractive plausible alternative interpretation to account for the absence of an N400 effect in response to certain semantic anomalies, as reported in previous studies. The single- stream Retrieval– Integration account posits the P600 as an index of integration, further predicting that its amplitude varies continuously with integrative effort. Here, we directly test these competing hypotheses using a context manipulation design in which a semantically attrac-tive alternative is either available or not, and target word plausibility is varied across three levels. An initial self- paced reading study revealed graded reading times for plausibility, suggesting differential integration effort. A subsequent ERP study showed no N400 differences across conditions, and that P600 amplitude is graded for plausibility. These findings are inconsistent with the interpretation of the N400 as an index of integration, as no N400 effect emerged even in the absence of a semantically attractive alternative. By contrast, the link between plausibility, reading times, and P600 amplitude supports the view that the P600 is a continuous index of integration effort. More generally, our results support a single- stream architecture and eschew the need for multi- stream accounts.
Description
Funding Information: This work was funded by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Project‐ID 232722074—SFB 1102. Publisher Copyright: © 2023 The Authors. Psychophysiology published by Wiley Periodicals LLC on behalf of Society for Psychophysiological Research.
Date
2023-09
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Research Projects
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Keywords
ERPs, Eeg, Language comprehension, N400, P600, Psycholinguistics
Citation
Aurnhammer, C, Delogu, F, Brouwer, H & Crocker, M W 2023, 'The P600 as a continuous index of integration effort', Psychophysiology, vol. 60, no. 9, e14302, pp. 1-28. https://doi.org/10.1111/psyp.14302