Fig. 1.

BMI setup. Patients were required to learn SMR desynchronization, measured with a 16-channel EEG system overlying the ipsilesional motor cortex. The EEG system was coupled with either hand or arm orthosis that supported reaching and grasping movements during BMI training. BMI training aimed to improve upper arm extension and flexion when using arm orthosis (reaching) and finger extension and flexion when using hand orthosis (grasping). The sensorimotor rhythm (SMR) power recorded from the ipsilesional electrodes was translated into movement of the orthosis. A threshold calculated as the point of equal distance to the mean of the power distribution during rest and motor intention calculated over the last 15 s defined rest and motor intention classification areas. When the SMR power was continuously in the motor intention classification area for 200 ms, the orthosis moved; the orthosis stopped when returned to the rest classification area for 200 ms and maintained the previous state otherwise. The same BMI principle was applied when training reaching movements with the arm orthosis. The experimental group received contingent feedback, linking SMR activity with movement execution supported by hand and arm orthoses; the control group received sham feedback, in which random movement of hand and arm orthoses was not linked to brain rhythms