Stimulating a specific brain area in cats caused them to exhibit rage-like behaviors that ceased upon cessation of stimulation.

“Eventually his electrode landed in a site and he provided electrical stimulation to the cat that caused this otherwise passive purring relaxing cat to suddenly go into an absolute rage. So arched back, hissing hair up. So called piloerection, where the hairs go up, animals try to make themselves as big as possible often when they're aggressive. Drooling, maybe even spitting, believe it or not, cats and other animals can do this. And the cat tried to attack him or anyone else, and anything else, even inanimate objects when he stimulated this particula brain area.”