The chemical components of fear amount to a chain reaction in the brain that begins with a traumatic stimulus that causes the discharge of powerful chemicals. These chemicals then cause your heart to race, the hairs on the back of your neck to rise, rapid breathing and a tensing of the muscles.
In that moment, you’re either consciously or unconsciously deciding, “fight or flight.” Do you stay and face the danger or run? What you decide depends on how dangerous the threat is and how you’ve been trained to deal with it.
A mouse running across the kitchen floor may cause you to automatically leap up onto a chair whereas the fear of speaking to a large audience of people may cause you to think through the fear and perform.
Fear usually causes the automatic response. Billions of brain cells take over to process the information available through your sensory perception and trigger a response. Now, research scientists know that certain parts of the brain are the culprits to triggering responses to fear.
These special, sensory areas of the brain are:
As you can see, you can’t avoid the brain’s sensory receptors which collect the data that can create fear unless one or more parts of the body are damaged. Even then, other receptors in other parts of the body become more acute to make up for the damaged area.
For example, a person who is blind may develop excellent audio receptors that surpass what sighted humans can hear. All of these physical reactions to outside stimulus alerts the brain to danger and creates a “fight or flight” fear response.