Freezing occurs when the amygdala – a crucial structure in the brain’s fear circuitry – detects an attack and signals the brainstem to inhibit movement. It happens in a flash, automatically and beyond conscious control.
It’s a brain response that rapidly shifts the organism into a state of vigilance for incoming attacks and avenues of escape. Eyes widen, pupils dilate. Hearing becomes more acute. The body is primed for fight or flight. But as we shall see, neither fight nor flight necessarily follows.
Simultaneously with the freeze response, the fear circuitry unleashes a surge of “stress chemicals” into the prefrontal cortex, the brain region that allows us to think rationally – to recall the bedroom door is open, or that people are in the dorm room next door, for example, and to make use of that information. But the surge of chemicals rapidly impairs the prefrontal cortex. That’s because, despite our dominant role on the planet now, we evolved as prey, and when a lion or tiger is upon us, stopping to think is fatal.