Abstract
Objective: A motor imagery (MI)-based brain-computer interface (BCI)
enables users to engage with external environments by capturing and decoding
electroencephalography (EEG) signals associated with the imagined movement of
specific limbs. Despite significant advancements in BCI technologies over the past 40
years, a notable challenge remains: many users lack BCI proficiency, unable to produce
su!ciently distinct and reliable MI brain patterns, hence leading to low classification
rates in their BCIs. The objective of this study is to enhance the online performance of
MI-BCIs in a personalized, biomarker-driven approach using transcranial alternating
current stimulation (tACS).
Approach: Previous studies have identified that the peak
power spectral density (PSD) value in sensorimotor idling rhythms is a neural correlate
of participants’ upper limb MI-BCI performances. In this active-controlled, single-blind
study, we applied 20 minutes of tACS at the participant-specific, peak μ frequency in
resting-state sensorimotor rhythms (SMRs), with the goal of enhancing resting-state
μ SMRs.
Main Results: After tACS, we observed significant improvements in event-
related desynchronizations (ERDs) of μ sensorimotor rhythms (SMRs), and in the
performance of an online MI-BCI that decodes left versus right hand commands in
healthy participants (N=10) —but not in an active control-stimulation control group
(N=10). Lastly, we showed a significant correlation between the resting-state μ SMRs
and μ ERD, o”ering a mechanistic interpretation behind the observed changes in online
BCI performances.
Significance: Our research lays the groundwork for future non-
invasive interventions designed to enhance BCI performances, thereby improving the
independence and interactions of individuals who rely on these systems
Brain-computer interface (BCI), Motor imagery (MI), EEG, Transcranial
alternating current stimulation (tACS), Sensorimotor rhythms (SMRs)
Authors
H Liu, D., Kumar, S., Alawieh, H., Samuel Racz, F., & del R Millán, J.
https://doi.org/10.1088/1741-2552/ada980