Dynamics of cortical and corticomuscular connectivity during planning and execution of visually guided steps in humans
- 2022-03-03.
/pmc/articles/PMC7614067/ /pubmed/35238339
The cortical mechanisms underlying the act of taking a step - including planning, execution, and modification - are not well understood. We hypothesized that oscillatory communication in a parieto-frontal and corticomuscular network is involved in the neural control of visually guided steps. We addressed this hypothesis using source reconstruction and lagged coherence analysis of electroencephalographic (EEG) and electromyographic (EMG) recordings during visually guided stepping and two control tasks that aimed to investigate processes involved in (1) preparing and taking a step; and (2) adjusting a step based on visual information. Steps were divided into planning, initiation, and execution phases. Taking a step was characterized by an up-regulation of beta/gamma coherence within the parieto-frontal network during planning followed by a down-regulation of alpha and beta/gamma coherence during initiation and execution. Step modification was characterized by bi-directional modulations of alpha and beta/gamma coherence in the parieto-frontal network during the phases leading up to step execution. Corticomuscular coherence did not exhibit task-related effects. We suggest that these task-related modulations indicate that the brain makes use of communication through coherence in the context of large scale, whole body movements, reflecting a process of flexibly fine-tuning inter-regional communication to achieve precision control during human stepping.