Prediction is production: ERP evidence in sentence comprehension

Martin, C. 1, 2 , Branzi, F. 3 & Bar, M. 4

1 BCBL, San Sebastian, Spain
2 Ikerbasque, Bilbao, Spain
3 ,Manchester, UK
4 Bar-Ilan University, Tel-Aviv, Israel

Language comprehension is predictive. Readers predict upcoming words during sentence processing, when the sentence context is highly constrained. Recently, several frameworks proposed that prediction is production, meaning that the production system is implicitly used for prediction during language comprehension. We tested this argument by comparing two groups of readers. The articulatory suppression (AS+) group had to read constrained sentences while pronouncing the syllable ?TA? on each word. By applying such AS, we attempted to block the production system. The control (AS-) group had to read the same sentences, while performing tongue-tapping on each word. This group was also performing double-tasking, but without taxing the production system. One hundred sentences were presented, half of them containing the most expected target word, half of them an unexpected one. Electroencephalography was recorded during reading, and Event-Related Potentials were measured, time-locked on the critical noun and the preceding article. The AS- group showed significant N400 effects both on the noun and the preceding article, replicating the classical word prediction effect. The AS+ group showed significant N400 effect on the noun, but not on the article. Those results suggest that articulatory suppression hinders prediction during sentence comprehension, which supports the claim that prediction is production.