Think to move and move: Slow brain potential biofeedback in severe motor paralysis

A series of experiments (Birbaumer et al., 1990) have established that self-induced cortical negativity depolarizes underlying cortical cell assemblies and positivities attenuate excitation of dendritic nets. Biofeedback of cortical positivity was found to be clinically useful for the treatment of drug-resistant epilepsy in two controlled studies. First data are reported on a new feedback system, which allows self-control of right versus left hemi-spheric differences and simultaneous increase and decrease of central positivity and negativity. Then 10 healthy volunteers, 10 partially paralyzed patients and 2 totally paralyzed patients ("locked in" syndrome) were tested. Paralyzed patients exhibited superior performance in the task compared to healthy subjects. The self-regulation of the four cortical signals can be used by these patients to communicate with their environment.