How Your Brain Processes Spine-tingling Fear

With celebrations like Halloween and Día de los Muertos (Day of the Dead), it’s the ideal time to indulge in all things spooky, horrific and honour the dead. Halloween, in particular, is perfect if you are seeking that rush from a fear-inducing scare. Ghosts, goblins, scary movies, zombie costumes…it’s all part of the agenda! Perhaps you spent Halloween catching up on The Walking Dead or American Horror Story? Or maybe you ventured into a haunted house?

Fight-or-Flight

Whatever your tastes may be, when faced with spine-tingling situations, your brain enters into fight-or-flight mode. This mode is a primitive survival mechanism, in which your body undergoes a stress response to a perceived threat in your surrounding environment. Originally, this reaction emerged from years of ancestors attempting to circumvent predators and escape danger. Nowadays, however, it is more common for us to experience those feelings in response to mental threats. These threats are more likely to cause some psychological distress as opposed to harm us physically.

The Amygdala

The amygdala is what handles our fight-or-flight response. It’s the part of our brain involved in experiencing emotion and an integral part of fear processing. Nevertheless, it is unable to distinguish a physical threat from a mental one. So while sweaty palms and anxiety may make more sense when confronted by a hungry lion, they may also manifest in undesirable scenarios such as during job interviews or scary movies.

A lot of evidence supports the involvement of the amygdala with fear processing. For instance, in a particular study, this brain region was completely removed in rats. Consequently, these rats no longer displayed fearful or avoidance behaviors towards their number one enemy – the cat.

When you watch a horror movie, the sudden appearance of the grotesque villain acts a stimulus and will trigger a signal in your amygdala. In response to a perceived threat, it releases a brain chemical called glutamate. The chemical acts on two other regions of your brain. The first signal is sent deep down into the base of the brain, into an area called the mid-brain.

Adrenaline and Dopamine Rush

Unfortunately, we have little control over this area. It makes us involuntarily jump or freeze, which isn’t ideal if you’ve got a bowl of popcorn in your lap. The second signal is sent to the hypothalamus, a section of the brain responsible for producing hormones. The hypothalamus triggers our autonomic nervous system – which is how our fight or flight instinct starts to kick in. As a result, the blood pressure and heart rate go up and adrenaline and dopamine (the brain’s “reward hormone”) are pumped throughout the body. These hormones help our bodies prepare for the fight or run of our lives, which is why you feel such a rush whenever you’re scared.

Your Brain’s Chemical Makeup

Ever wondered, however, why some people seem to enjoy horror films more than others? Or maybe why some people gravitate towards extreme sports or risky activities? It appears that certain individuals enjoy these experiences of fear and the accompanying rush more than others. Why? Well, it could be due to underlying differences in the brain’s chemistry. At Vanderbilt University, for example, it was revealed that chemical responses differed in groups of people when faced with thrilling situations. While dopamine is released in response to scary or thrilling situations, in some individuals, their brain lacks a “brake” on the dopamine release and re-uptake in the brain.

As a result, they experience more reward and pleasure in spooky or risky situations and even higher levels of dopamine in the brain. This explains why some of us cower in fear at the mere mention of zombies, while others feel butterflies of excitement. So, still afraid of things that go bump in the night?

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