Happy Halloween! It’s a good time of year to think about the neuroscience of fear. Fear is one of the most visceral emotional reactions you can have, so there must be a clear reaction in the brain when you get scared.
One study (Dilger et al., 2003) looked at the brains of ten people who were afraid of spiders—and we’re not talking mild heebie-jeebies, but certifiable DSM-diagnosed arachnophobia. A spider is probably the absolute worst thing they could see while lying in a dark brain scanner. Can you guess what the researchers did next? That’s right, they showed them spiders while lying in a dark brain scanner.
Unsurprisingly, their brains reacted, and were compared to the brains of people who were not afraid of spiders. That resulted in an image of what fear looks like in the brain. Here it is—the seat of terror, the source of all that we abhor, a single image of pure, absolute horror:
Okay, maybe I built that up too much. But you can see how powerful even a tiny part of the brain can be. That dot is the left amygdala. One of the amygdala’s functions is to connect emotions with memories, ensuring that we avoid anything that causes us great fear. That fear can be useful; one patient, known as S.M., had complete destruction of both amygdala, and lives without fear of anything, including spiders, scary movies, and dangerous people. Unfortunately, her lack of fear has led her into several life-threatening situations that she was not motivated to avoid.
So if you find yourself recoiling from any spiders, ghosts, or goblins this Halloween, you can thank your amygdala for keeping you safe.