SELF-REGULATION OF SLOW CORTICAL POTENTIALS IN COMPLETELY PARALYZED HUMAN PATIENTS

The study was intended to answer the question whether self-regulation of brain activity can be operantly learnt when the brain is disconnect ed from motor periphery. Two neurological patients with nearly complet e motor paralysis learned bi-directional control of their slow cortica l potentials (SCP) at vertex. After 4-6 weeks training both patients c ould reliably differentiate between SCP shifts in a negative versus po sitive direction. With one patient, training has been continued for a subsequent 4 months, which resulted in precise self-control, i.e. the patient was able to produce positive SCP shifts on command with an acc uracy of about 95%. This indicates that self-regulation of cortical ex citability las manifested in the SCP) does not require feedback loops from the periphery. Although we cannot rule out that healthy subjects may employ behavioral strategies such as muscle contractions or change s in breathing, obviously humans can also control their SCP without us ing these strategies. (C) 1998 Elsevier Science Ireland Ltd. All right s reserved.