A BCI-Based Vibrotactile Neurofeedback Training Improves Motor Cortical Excitability During Motor Imagery.

Nikita A Grigorev,Natalia N Shusharina,Anna Udoratina,Victor B Kazantsev,Alexander Ya Kaplan,Maksim V Lukoyanov,Alexander E Hramov,Susanna Gordleeva,Andrey O Savosenkov

doi:10.1109/tnsre.2021.3102304

Abstract

In this study, we address the issue of whether vibrotactile feedback can enhance the motor cortex excitability translated into the plastic changes in local cortical areas during motor imagery (MI) BCI-based training. For this purpose, we focused on two of the most notable neurophysiological effects of MI - the event-related desynchronization (ERD) level and the increase in cortical excitability assessed with navigated transcranial magnetic stimulation (nTMS). For TMS navigation, we used individual high-resolution 3D brain MRIs. Ten BCI-naive and healthy adults participated in this study. The MI (rest or left/right hand imagery using Graz-BCI paradigm) tasks were performed separately in the presence and absence of feedback. To investigate how much the presence/absence of vibrotactile feedback in MI BCI-based training could contribute to the sensorimotor cortical activations, we compared the MEPs amplitude during MI after training with and without feedback. In addition, the ERD levels during MI BCI-based training were investigated. Our findings provide evidence that applying vibrotactile feedback during MI training leads to (i) an enhancement of the desynchronization level of mu-rhythm EEG patterns over the contralateral motor cortex area corresponding to the MI of the non-dominant hand; (ii) an increase in motor cortical excitability in hand muscle representation corresponding to a muscle engaged by the MI.

Highlights

We focused on two of the most notable neurophysiological effects of motor imagery (MI) – the event-related desynchronization (ERD) level and the increase in cortical excitability assessed with navigated transcranial magnetic stimulation
Our findings provide evidence that applying tactile feedback during MI leads to (i) an enhancement of the desynchronization level of mu-rhythm EEG patterns over the contralateral motor cortex area corresponding to the MI of the non-dominant hand; (ii) an increase in motor cortical excitability in hand muscle representation corresponding to a muscle engaged by the MI
We explored the effects of vibrotactile feedback on MI brain-computer interface (BCI)-based training

Summary

Introduction

As a variation of NF, training in motor imagery (MI) based BCI is believed to be a helpful technique in neurorehabilitation therapy of people with impaired motor functions (e.g. patients with tetraplegia, spinal cord injury) and patients with brain injuries (e.g. stroke, amyotrophic lateral sclerosis) [4,5,6]. In some cases, visual feedback is not suitable, for example, for patients with an impaired visual system [15] or under the circumstances of the visual channel overload [16,17,18,19]. For these purposes, other feedback modalities have been explored. Most MIbased NF system use orthosis and exoskeletons as kinesthetic feedback for research [24, 25, 36, 37] or for clinical

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