The use of transcranial direct current stimulation (tDCS) has been related to the improvement of motor
and learning tasks. The current research studies the effects of an asymmetric tDCS setup over brain
connectivity, when the subject is performing a motor imagery (MI) task during five consecutive days.
A brain–computer interface (BCI) based on electroencephalography is simulated in offline analysis to
study the effect that tDCS has over different electrode configurations for the BCI. This way, the BCI
performance is used as a validation index of the effect of the tDCS setup by the analysis of the classifier
accuracy of the experimental sessions. In addition, the relationship between the brain connectivity and the
BCI accuracy performance is analyzed. Results indicate that tDCS group, in comparison to the placebo
sham group, shows a higher significant number of connectivity interactions in the motor electrodes during
MI tasks and an increasing BCI accuracy over the days. However, the asymmetric tDCS setup does not
improve the BCI performance of the electrodes in the intended hemisphereThis research has been carried out in the framework
of the project Walk — Controlling lower-limb
exoskeletons by means of BMIs to assist people with
walking disabilities (RTI2018-096677-B-I00Funded by the Spanish Ministry of Science and Innovation,
the Spanish State Agency of Research and the European
Union through the European Regional Development
Fund;by the Consellería de Innovación,
Universidades, Ciencia y Sociedad Digital (Generalitat
Valenciana) and the European Social Fund in
the framework of the project ‘Desarrollo de nuevas
interfaces cerebro-m´aquina para la rehabilitaci`on de
miembro inferior’ (GV/2019/009).Also, the Mexican
Council of Science and Technology (CONACyT)
provided J. A. Gaxiola-Tirado his scholarshi
