Halloween Special: Fear Itself

Fear is universal and complex - and the science behind it is downright fascinating.

by Kelly O'Brien

Think about the last time you saw a shark while snorkeling, or had a VITRAN bus hurtling towards you around a tight curve, or were caught up in the frenzy of prepping your house for a fast-approaching hurricane. Remember the hollow feeling in your stomach and the sudden snap to attention of all your senses? No matter what's causing it, fear all feels the same.

That's because the fear response is biological first, and psychological second. Anytime we feel that familiar jolt of fear, our brains are going through the same process. We see (/hear/smell/whatever) something, and that information travels directly into our amygdala, an almond-shaped portion of our brain that processes our initial emotional responses to external stimuli. When we perceive something as a threat, the amygdala triggers a rush of chemicals and hormones that result in all the various physical responses to fear - your heart starts pounding, and a chill shudders its way down your spine, while all those little hairs on the back of your neck are standing right up. In the meantime, though, the information your senses picked up on (the shark, bus, hurricane) gets passed along to the pre-frontal cortex, which takes a deep breath and logically assesses the risk-factor.

This secondary assessment is what sets the human fear response apart from the simple, multiple-choice, fight-or-flight response employed by most of the animal kingdom. The analysis by the pre-frontal cortex is what allows us to temper the chemical response with reason; yes, that noise outside was unfamiliar, but the chances that it was the footstep of a crazed psycho-killer, come to murder you in your sleep are really very slim, says the pre-frontal cortex.

So once it gets past the hard-wired, survival impulses governed by the amygdala, our experiences of fear get far more complex. Take, for example, our tendency to seek out certain frightening situations. What is it about our neurological make-up that makes us enjoy Halloween and horror movies? Bungee jumping and skydiving? Heck, even dating the bad boy/girl? These things scare us, and we like it - why? Well, as it turns out, the parts of our brain that process fear overlap quite a bit with those that process pleasure. The aforementioned rush of chemicals that we get when something startles us, can be remarkably similar to the one we get when we're enjoying something. (Like ice cream! What were you thinking about!?) So far, neuroscientists have had a hard time coming up with a consistent answer for why our brains have evolved that way. For now, though, we can just be glad they did - otherwise, what fun would Halloween be?

October 2009

Sources:
"That Nearly Scared Me to Death! Let's Do it Again, " Wired Magazine, 10/31/07
"Using Rats to Trace Anatomy of Fear, Biology of Emotion ," New York Times, 11/5/96
"Scent of Fear Puts Brain in Emergency Mode ," New Scientist, 7/29/09