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 minimal 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 manipulating 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 (231–407 ms; 506–622 ms), largely replicating the Sentence Superiority Effect of prior RPVP studies. Each cluster showed sensitivity to syntactic frame, first with increased activity for yes/no questions and then for declaratives. No effects of verb argument structure were obtained. The RPVP paradigm's sensitivity to both the sentence-list contrast and to certain grammatical details highlights its value for probing the neurobiology of syntax.