Effects of tDCS on Real-Time BCI Detection of Pedaling Motor Imagery

Abstract

The purpose of this work is to strengthen the cortical excitability over the primary motor cortex (M1) and the cerebro-cerebellar pathway by means of a new transcranial direct current stimulation (tDCS) configuration to detect lower limb motor imagery (MI) in real time using two different cognitive neural states: relax and pedaling MI. The anode is located over the primary motor cortex in Cz, and the cathode over the right cerebro-cerebellum. The real-time brain–computer interface (BCI) designed is based on finding, for each electrode selected, the power at the particular frequency where the most difference between the two mental tasks is observed. Electroencephalographic (EEG) electrodes are placed over the brain’s premotor area (PM), M1, supplementary motor area (SMA) and primary somatosensory cortex (S1). A single-blind study is carried out, where fourteen healthy subjects are separated into two groups: sham and active tDCS. Each subject is experimented on for five consecutive days. On all days, the results achieved by the active tDCS group were over 60% in real-time detection accuracy, with a five-day average of 62.6%. The sham group eventually reached those levels of accuracy, but it needed three days of training to do so.

Review of tDCS Configurations for Stimulation of the Lower-Limb Area of Motor Cortex and Cerebellum

“…The idea behind targeting the cerebellar motor area pathway in such a way was that the motor area was excited and the cerebellum was inhibited in order to produce a benefit in MI. In [ 69 ], a similar setup, following this principle too, was proven with other MI protocols. This setup was tested in different polarity configurations [ 70 ].…”

“…There are three works that use the HD-tDCS property to stimulate several pathways simultaneously that have reported significant and promising results. The Cz-cerebellum pathway [ 69 ] obtained inferior results to those of the Cz, cerebellum-FC2 pathway [ 70 ]. Another work, which has also shown promising results, can be seen in [ 66 ].…”

Data Augmentation for Motor Imagery Signal Classification Based on a Hybrid Neural Network

“…As an important technology focused on rehabilitation [71,72], MI-BCI aims to replace or recover the motor nervous system functionality that is lost due to disease or injury. In the application of DA for MI-EEG, future work could extend this work in clinical BCI tasks.…”

Assistance Robotics and Biosensors

“…In “Effects of tDCS on Real-Time BCI Detection of Pedaling Motor Imagery” [ 6 ] the authors sought to strengthen the cortical excitability over the primary motor cortex (M1) and the cerebro-cerebellar pathway by means of a new transcranial direct current stimulation (tDCS) configuration to detect lower limb motor imagery (MI) in real time using two different cognitive neural states: relaxed and pedaling MI. In this case, the use of software or hardware techniques with the purpose of improving the reception of signals was again treated.…”