Reinforcement of Intra- and Inter-Species Aggression with Intracranial Stimulation

Intracranial stimulation was used as a reinforcer to conditionfighting in paired rats. Stimulation for an implanted animalwas made contingent upon responses which successively approximatedthose typical of attack. A stable pattern of aggression developed,the maintenance of which was possible on intermittent reinforcementschedules although at depressed frequencies. An implanted ratalso readily initiated contact with a cat and made consistent,aggressive approaches toward a squirrel monkey. The aggressionobserved appeared to be a function of operant reinforcementsince extinction occurred when the intracranial stimulationcontingency was removed.