Cortical effects of user training in a motor imagery based brain–computer interface measured by fNIRS and EEG

The present study aims to gain insights into the effects of training with a motor imagery (MI)-based brain–computer interface (BCI) on activation patterns of the sensorimotor cortex. We used functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) to investigate long-term training effects across 10 sessions using a 2-class (right hand and feet) MI-based BCI in fifteen subjects. In the course of the training a significant enhancement of activation pattern emerges, represented by an [oxy-Hb] increase in fNIRS and a stronger event-related desynchronization in the upper β-frequency band in the EEG. These effects were only visible in participants with relatively low BCI performance (mean accuracy≤70%). We found that training with an MI-based BCI affects cortical activation patterns especially in users with low BCI performance. Our results may serve as a valuable contribution to the field of BCI research and provide information about the effects that training with an MI-based BCI has on cortical activation patterns. This might be useful for clinical applications of BCI which aim at promoting and guiding neuroplasticity. •Effects of brain–computer interface (BCI) training were investigated.•Cortical activation patterns of motor imagery (MI) training were long-term monitored.•Functional near-infrared spectroscopy (fNIRS) and EEG were used.•MI based BCI training affects cortical activation patterns.•Effects were found especially in users with low BCI performance.