Whether it’s a haunted house, or a scary movie, this is the night for frights.  And what exactly is fear?

A chemical reaction in the brain that assures survival, or attempts to.

Psychologist Laurence Abrams explains.  “The body adapts into kind of a crouched position.  The blood pumps faster.  The adrenaline pumps.  And you’re prepared to either fight to protect yourself or flee to protect yourself.”

The chemical alarm in your brain is glutamate.  That’s the danger signal that sets off all the other responses. 

“Certain things have always triggered fear in people,” Dr. Abrams tells KTRH News.  “Darkness, helplessness in the face of monsters, threats to the body, those are the things that are classically used by movies to scare you to death.”

The hypothalamus picks up on the danger system and determines either a flight or fight response.  Glucose goes into the blood stream in case you need to run.  The adrenal gland secretes cortisol and adrenaline.

“Your imagination can literally scare you to death,” says Dr. Abrams.  “It can overpower your physiology and stop your heart.  Fear is a powerful chemical reaction.”