Why do we avoid scary things?

About the episode

The researchers were curious what happens in the brain when we look away from something scary. To find out, they did an experiment with fruit flies.

Why do we cover our eyes in this scene from a horror movie? Or do we look away when someone else does something scary? This response, of course, varies from person to person, but it can be driven by the same mechanism.

Now, you can’t look at a lot of things in the brains of humans – especially from an ethical perspective – that you can see in fruit flies. First, they looked at what happens in the brains of fruit flies that have previously been spooked when they encounter a spider-like object in their path. Flies quickly turn away in this situation. Fruit flies that weren’t on high alert didn’t.

When they next looked at this reaction in the brain, they found that a group of about 20 to 30 neurons fired waves of the chemical tachykinin. If they genetically modified the frightened flies in such a way as to disrupt this mechanism, they would no longer turn away from the spider. This suggests that this group of neurons is necessary for this aversive response.

Why would you want to know more about this? Ultimately, the researchers hope their experiments will contribute to a better understanding of anxiety disorders and phobias and to the search for better treatments.

Much more research will be needed for this.

Learn more here: Fear is in the eye of the beholder.