Brain Processes Involved in Motor Planning Are a Dominant Factor for Inducing Event-Related Desynchronization

Kosei Nakayashiki; Hajime Tojiki; Yoshikatsu Hayashi; Shiro Yano; Toshiyuki Kondo

doi:10.3389/fnhum.2021.764281

Frontiers in Human Neuroscience (Nov 2021)

Brain Processes Involved in Motor Planning Are a Dominant Factor for Inducing Event-Related Desynchronization

Kosei Nakayashiki,
Hajime Tojiki,
Yoshikatsu Hayashi,
Shiro Yano,
Toshiyuki Kondo

Affiliations

Kosei Nakayashiki: Department of Computer and Information Sciences, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
Hajime Tojiki: Department of Computer and Information Sciences, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
Yoshikatsu Hayashi: Biomedical Science and Biomedical Engineering, School of Biological Sciences, University of Reading, Whiteknights, Reading, United Kingdom
Shiro Yano: Department of Computer and Information Sciences, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
Toshiyuki Kondo: Department of Computer and Information Sciences, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan

DOI: https://doi.org/10.3389/fnhum.2021.764281
Journal volume & issue: Vol. 15

Abstract

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Event-related desynchronization (ERD) is a relative attenuation in the spectral power of an electroencephalogram (EEG) observed over the sensorimotor area during motor execution and motor imagery. It is a well-known EEG feature and is commonly employed in brain-computer interfaces. However, its underlying neural mechanisms are not fully understood, as ERD is a single variable correlated with external events involving numerous pathways, such as motor intention, planning, and execution. In this study, we aimed to identify a dominant factor for inducing ERD. Participants were instructed to grasp their right hand with three different (10, 25, or 40%MVF: maximum voluntary force) levels under two distinct experimental conditions: a closed-loop condition involving real-time visual force feedback (VF) or an open-loop condition in a feedforward (FF) manner. In each condition, participants were instructed to repeat the grasping task a certain number of times with a timeline of Rest (10.0 s), Preparation (1.0 s), and Motor Execution (4.0 s) periods, respectively. EEG signals were recorded simultaneously with the motor task to evaluate the time-course of the event-related spectrum perturbation for each condition and dissect the modulation of EEG power. We performed statistical analysis of mu and beta-ERD under the instructed grasping force levels and the feedback conditions. In the FF condition (i.e., no force feedback), mu and beta-ERD were significantly attenuated in the contralateral motor cortex during the middle of the motor execution period, while ERD in the VF condition was maintained even during keep grasping. Only mu-ERD at the somatosensory cortex tended to be slightly stronger in high load conditions. The results suggest that the extent of ERD reflects neural activity involved in the motor planning process for changing virtual equilibrium point rather than the motor control process for recruiting motor neurons to regulate grasping force.

Published in Frontiers in Human Neuroscience

ISSN: 1662-5161 (Online)
Publisher: Frontiers Media S.A.
Country of publisher: Switzerland
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry
Website: http://www.frontiersin.org/human_neuroscience

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