For example, Anderson’s lab has investigated fruit flies that become much more active when they see a moving shadow like the one cast by a flying predator.
That sort of behavior is typical of a persistent brain state called defensive arousal.
In mice, the answer appears to be specialized brain cells that become hyperactive when a mouse detects a threat and that return gradually to normal after the threat has passed.
There’s no way to know if animals have angry feelings, says Dayu Lin, a neuroscientist at New York University.
In people, this region is near the bottom of the hypothalamus, just above the pituitary gland.
HAMILTON: That idea is central to Anderson’s latest book, “The Nature Of The Beast: How Emotions Guide Us.” He says, to study emotions in animals, scientists need to set aside their own perceptions of states like anger, fear, sadness or joy.
For example, fruit flies in Anderson’s lab become much more active when they see a moving shadow that resembles a flying predator.
HAMILTON: And they keep hopping long after the shadow is gone.
And I’d probably jump every time I saw a snakelike object in front of me, even if it was a stick.
HAMILTON: In mice, the answer appears to be specialized brain cells that become hyperactive when an animal detects a threat and gradually return to normal after the threat has passed.
HAMILTON: In people, it’s near the bottom of the hypothalamus, just above the pituitary gland.
Lin says doctors sometimes use deep brain stimulation to deactivate the aggression circuit in extremely violent psychiatric patients.
HAMILTON: For a person with PTSD, even a minor event can produce a stress and fear response that lasts for hours.