Seizure severity and acquisition and performance of operant tasks in a monkey model.

Several studies utilizing an alumina-gel monkey model demonstrated a relationship between degree of epileptic activity and learning difficulty. Three operant tasks were employed: single-unit, gross-motor positive reinforcement, and avoidance conditioning. The data indicated that the number of hours needed to learn any one of the tasks increased with seizure frequency and/or number of EEG interictal bursts. The learning impairment appeared to be a function of the relevance of the required response to the site of the epileptogenic focus.