Valeriani, Davide, and Kristina Simonyan. 2021. “The Dynamic Connectome of Speech Control”. Philosophical Transactions of the Royal Society B 376 (1836).
rstb.2020.0256.pdf2.16 MB
supplementary_material.pdf252.63 KB
Abstract
Speech production relies on the orchestrated control of multiple brain regions. The specific, directional influences within these networks remain poorly understood. We used regression dynamic causal modeling to infer the whole-brain directed (effective) connectivity from functional magnetic resonance imaging data of 36 healthy individuals during the production of meaningful English sentences and meaningless syllables. We identified that the two dynamic connectomes have distinct architectures that are dependent on the complexity of task production. Speech was regulated by a dynamic neural network, the most influential nodes of which were centered around superior and inferior parietal areas and influenced the whole-brain network activity via long-ranging coupling with primary sensorimotor, prefrontal, temporal, and insular regions. In contrast, syllable production was controlled by a more compressed, cost-efficient network structure, involving sensorimotor cortico-subcortical integration via superior parietal and cerebellar network hubs. These data demonstrate that the mechanisms by which the neural network reorganizes the connectivity of its influential regions from supporting the fundamental aspects of simple vocal motor output of syllables to multimodal information processing of speech motor output.