Effect of EEG Biofeedback on Convulsive Response to Monomethylhydrazine in the Rhesus Monkey

Abstract : Toxic and convulsive responses to monomethylhydrazine (MMH) were compared in two groups of rhesus monkeys. One group received 12 weeks of feedback training with reinforcement provided for the production of rhythmic central cortical 12-14 Hz EEG activity (the sensorimotor rhythm or SMR) in the absence of movement and concurrent 8-11 Hz EEG activity. A second group was studied also but without feedback training. Three of the four trained animals demonstrated reliable acquisition of the rewarded response. Following training a convulsive dose of MMH was administered to both groups. Trained animals showed a significantly prolonged latency to generalized seizures, fewer overall seizures, and a greater incidence of sustained quiescent behavior. Toxic responses, including emesis and episodes of agitated behavior, were comparable among the two groups. These findings indicate that threshold for MMH induced seizures can be modified in primates through EEG feedback training, as shown previously in the cat. A specific change in central motor control mechanisms is proposed as an explanation for this effect.