TY - JOUR T1 - Modulation in Alpha Band Activity Reflects Syntax Composition: An MEG Study of Minimal Syntactic Binding JF - bioRxiv DO - 10.1101/2021.07.09.451797 SP - 2021.07.09.451797 AU - Sophie M. Hardy AU - Ole Jensen AU - Linda Wheeldon AU - Ali Mazaheri AU - Katrien Segaert Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/07/09/2021.07.09.451797.abstract N2 - Successful sentence comprehension requires the binding, or composition, of multiple words into larger structures to establish meaning. Using magnetoencephalography (MEG), we investigated the neural mechanisms involved in binding of language at the level of syntax, in a task in which contributions from semantics were minimized. Participants were auditorily presented with minimal sentences that required binding (pronoun and pseudo-verb with the corresponding morphological inflection; “she grushes”) and wordlists that did not require binding (two pseudo-verbs; “cugged grushes”). Relative to the no binding wordlist condition, we found that syntactic binding in a minimal sentence structure was associated with a modulation in alpha band (8-12 Hz) activity in left-lateralized brain regions. First, in the sentence condition, we observed a significantly smaller increase in alpha power around the presentation of the target word (“grushes”) that required binding (−0.05s to 0.1s), which we suggest reflects an expectation of binding to occur. Second, following the presentation of the target word (around 0.15s to 0.25s), during syntactic binding we observed significantly decreased alpha phase-locking between the left inferior frontal gyrus and the left middle/inferior temporal cortex. We suggest that this results from alpha-driven cortical disinhibition serving to increase information transfer between these two brain regions and strengthen the syntax composition neural network. Together, our findings highlight that successful syntax composition is underscored by the rapid spatial-temporal activation and coordination of language-relevant brain regions, and that alpha band oscillations are critically important in controlling the allocation and transfer of the brain’s resources during syntax composition.Significance statement Essential to the power of human language is our ability to comprehend and bind together multiple words into larger sentence structures to establish meaning. In this study, we investigated the electrophysiological mechanisms of binding language at the level of syntax (i.e., relating to the grammatical features). Our MEG results reveal that syntactic binding, relative to no binding, is associated with modulation in alpha band activity (8-12 Hz), including less power increases and inter-regional phase-locking, within and among language-relevant brain regions in the left hemisphere. We suggest that these alpha oscillations help control the allocation of the brain’s resources (in particular within the left inferior frontal gyrus and the left middle/inferior temporal cortex) to support syntactic binding in language comprehension.Competing Interest StatementThe authors have declared no competing interest. ER -