Neurophysiological correlates of force control improvement induced by sinusoidal vibrotactile stimulation

Germer CM, Del Vecchio A, Negro F, Farina D, Elias LA (2020)


Publication Type: Journal article

Publication year: 2020

Journal

Book Volume: 17

Article Number: 016043

Journal Issue: 1

DOI: 10.1088/1741-2552/ab5e08

Abstract

Objective. An optimal level of vibrotactile stimulation has been shown to improve sensorimotor control in healthy and diseased individuals. However, the underlying neurophysiological mechanisms behind the enhanced motor performance caused by vibrotactile stimulation are yet to be fully understood. Therefore, here we aim to evaluate the effect of a cutaneous vibration on the firing behavior of motor units in a condition of improved force steadiness. Approach. Participants performed a visuomotor task, which consisted of low-intensity isometric contractions of the first dorsal interosseous (FDI) muscle, while sinusoidal (175 Hz) vibrotactile stimuli with different intensities were applied to the index finger. High-density surface electromyogram was recorded from the FDI muscle, and a decomposition algorithm was used to extract the motor unit spike trains. Additionally, computer simulations were performed using a multiscale neuromuscular model to provide a potential explanation for the experimental findings. Main results. Experimental outcomes showed that an optimal level of vibration significantly improved force steadiness (estimated as the coefficient of variation of force). The decreased force variability was accompanied by a reduction in the variability of the smoothed cumulative spike train (as an estimation of the neural drive to the muscle), and the proportion of common inputs to the FDI motor nucleus. However, the interspike interval variability did not change significantly with the vibration. A mathematical approach, together with computer simulation results suggested that vibrotactile stimulation would reduce the variance of the common synaptic input to the motor neuron pool, thereby decreasing the low frequency fluctuations of the neural drive to the muscle and force steadiness. Significance. Our results demonstrate that the decreased variability in common input accounts for the enhancement in force control induced by vibrotactile stimulation.

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How to cite

APA:

Germer, C.M., Del Vecchio, A., Negro, F., Farina, D., & Elias, L.A. (2020). Neurophysiological correlates of force control improvement induced by sinusoidal vibrotactile stimulation. Journal of Neural Engineering, 17(1). https://doi.org/10.1088/1741-2552/ab5e08

MLA:

Germer, Carina Marconi, et al. "Neurophysiological correlates of force control improvement induced by sinusoidal vibrotactile stimulation." Journal of Neural Engineering 17.1 (2020).

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