Poster A82, Tuesday, August 20, 2019, 10:15 am – 12:00 pm, Restaurant Hall
Readers are parallel processors: ERP evidence from the RPVP paradigm
Yun Wen1, Jonathan Mirault1, Joshua Snell1, Jonathan Grainger1;1Laboratoire de Psychologie Cognitive, Aix-Marseille Université and Centre National de la Recherche Scientifique, Marseille
A central issue addressed in reading research is whether skilled reading involves one-word-at-a-time incremental processing or parallel, cascaded, and interactive processing. Here we show that simultaneous processing of multiple words is possible, by combining EEG recordings with the novel rapid parallel visual presentation (RPVP) paradigm. In the RPVP paradigm, a sequence of four horizontally aligned words was briefly presented (i.e., 200 ms). In Experiment 1, the four words could either represent a grammatically correct sequence (e.g., “she can sing now”) or an ungrammatical scrambled sequence of the same words (e.g., “now she sing can”). The experimental task was to identify one post-cued word within the sequence (e.g., the post-cued word is “sing” in previous examples). In Experiment 2, the key manipulation was the same as Experiment 1 (grammatically correct sequences vs. ungrammatical scrambled sequences), and a grammaticality judgement task was used. Experiment 3 also used a grammaticality judgement task, and the critical comparison was between two types of ungrammatical sequences, i.e., the transposed-word sequences (e.g., “you that read wrong”, transposing two adjacent central words can form a grammatical sequence) and the control sequences (e.g., “you that read worry”, transposing two adjacent central words still forms an ungrammatical sequence). We report three key findings from this set of EEG experiments: (1) a reduced N400 effect was obtained in the grammatically correct sequences compared to the ungrammatical scrambled sequences, and this N400 sentence superiority effect was independent of the experimental tasks; (2) an N400 reduction was observed in the transposed-word sequences relative to the control sequences (the N400 transposed-word effect), and both types of ungrammatical sequences elicited the N400 effect relative to grammatical filler sequences; and (3) the ERP responses to word sequences presented in the RPVP paradigm are strikingly similar across experiments, revealing the consistent neural signature of parallel processing of multiple words. Our results suggest that an initial representation of sentence structure can be quickly generated on the basis of partial information extracted from several words in parallel, and this syntactic representation then constrains on-going identification processes through feedback to word identities as evidenced by the N400 sentence superiority effect. Furthermore, this elementary syntactic representation also constrains the range of possible word candidates at each position, and such top-down constraints together with the noisy bottom-up encoding of word order drive the N400 transposed-word effect. Taken together, our study provides converging evidence in favour of highly interactive processing operating between word-level and sentence-level representations during sentence reading, and demonstrates that the RPVP paradigm is a methodological advance that complements other widely-used paradigms in electrophysiological investigations of reading comprehension.
Themes: Reading, Syntax
Method: Electrophysiology (MEG/EEG/ECOG)