Proceedings of the Annual Meeting of the Cognitive Science Society

Language can occur in highly serial (speech) or fully parallel form (text), yet how our brains adapt to seriality differences is not understood. Here, we held modality constant (visual) and examined whether processing mechanisms underlying grammaticality detection are similar under Rapid Serial Visual Presentation (RSVP) and Rapid Parallel Visual Presentation (RPVP). To identify shared neural representations of grammaticality, we trained a classifier on magnetoencephalography (MEG) responses to grammatical and ungrammatical three-word phrases in one presentation mode and tested its generalization to the other. Behaviorally, accuracy was higher and reaction times faster for grammatical vs. ungrammatical phrases across presentation modes. Neurally, cross-presentation decoding revealed shared two-stage activity at word 2 across train-test directions, and an early shared representation at word 3 when trained on RPVP. We take the bidirectional representations at word 2 to capture combinatory processes and the asymmetry at word 3 as reflecting stronger global structure encoding in RPVP.