Figure 2

Experimental procedure during the BMI session.

(a) Calibration session, off-line: subjects were instructed to imagine clasping movements performed either with the left or the right hand as indicated by a visual cue (red arrow) without receiving any visual feedback. (b) The collected EEG data were then used to extract EEG correlates of motor imagery, to train a linear classifier and to extract subject specific spatial filters. (c) These parameters were then used in the on-line session, during which subjects were asked to control in real-time the movement of a cursor (black rectangle) by performing the same motor imagery task as in the calibration session.