Manipulating syntax without taxing working memory: MEG correlates of syntactic dependencies in a Verb-Second language
The neural basis of syntax is notoriously difficult to study without working memory and lexico-semantic confounds. To tackle these challenges, we presented dependencies in minimal Danish two-word sentences using Rapid Parallel Visual Presentation (RPVP), which eliminated the tem-poral delay between a filler and gap. Our stimuli involved dependencies high and low in the tree as a function of manipulating syntactic frame (declarative, yes/no question) and verb argument struc-ture (unergative, unaccusative, alternating unaccusative). Neural magnetoencephalography signals were increased and behaviour facilitated for sentences compared to list controls, replicating the Sentence Superiority Effect (SSE) of prior RPVP studies. Our left-lateral neural SSE at 231-407ms co-occurred with a right-lateral fronto-medial argument structure effect, while syntactic frame affected neural signals at 500-723ms. Thus hierarchically lower dependencies elicited faster neurophysiological correlates, raising the possibility that RPVP may offer a unique window into the brain's detection of syntax when removing temporally extended parsing decisions.