What Happens in the Brain When We Feel Fear

The fear reaction starts in the brain's amygdala region and spreads through the body to prepare the body for the best defense or flight reaction. Fear also triggers the release of stress hormones and the sympathetic nervous system.

During a dangerous situation, the brain becomes hyperalert, pupils dilate, the bronchi dilate, breathing accelerates, heart rate and blood pressure rise, blood flow and a stream of glucose to the skeletal muscles increase, and organs not vital in survival slow down, such as the gastrointestinal system.

We learn fear through observation, personal experiences, and through the instruction of spoken or written notes. The perception of control is vital to how we experience and respond to fear.

When you look to your friend at the haunted house, and she's quickly gone from screaming to laughing, socially, you're able to pick up on her emotional state, which can influence your own state.

An imbalance between excitement caused by fear and the sense of control may cause too much or too little excitement.

If the experience is seen as "too real," an extreme fear response can overcome the sense of control. But if the experience is not triggering enough to the emotional brain, or is too unreal to the thinking brain, the experience can end up feeling boring.