Mirror Visual Feedback as a Tool for Training Users to Achieve Control Over the BCI

Purpose: To evaluate Mirror Visual Feedback (MVF) as training for brain-computer interface (BCI) users. Around 20%-30% of subjects need more training to operate a BCI system that uses motor imagery. Electroencephalograms (EEGs) were recorded from 18 healthy subjects, using event related desynchronization (ERD) to observe the responses during the movement or movement intention of the hand for the conditions of Control, Imagination, and the MVF with the mirror box. Two groups of subjects were formed, Group 1: control, imagination, and MVF. Group 2: control, MVF, and imagination. There were significant differences in imagination conditions between groups using MVF before or after imagination (Right-hand p = 0.0403. Left-hand p = 0.00939). The illusion of movement through MVF is not possible in all subjects. However, even in those cases an increase in imagination when the subject used the MVF previously was found. The increase in the r2 of imagination in the right and left hands suggests crosslearning. The increase in motor imagery recorded with EEG after MVF suggests that the mirror box made it easier to imagine movements.