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 syntactic dependencies in Danish two-word sentences using Rapid Parallel Visual Presentation (RPVP), eliminating the temporal delay between displaced elements and their base-generated positions. Our stimuli involved various dependencies as a function of syntactic frame (declarative, yes/no question) and verb argument structure (unergative, unaccusative, alternating unaccusative). Behaviour was facilitated and magnetoencephalography responses were increased for sentences compared to list-controls in left fronto-temporal regions (231-407ms; 506-622ms), largely replicating the Sentence Superiority Effect of prior RPVP studies. Each cluster showed sensitivity to syntactic frame, with the earlier one likely reflecting basic structure detection and the second syntactic movement. No effects of verb argument structure were obtained. The RPVP paradigms sensitivity to both the sentence-list contrast and to certain grammatical details highlights its value for probing the neurobiology of syntax.