Hosted by Sandra Tsing Loh, The Loh Down on Science is a fun way to get your daily dose of science plus a dash of humor in less than two minutes.
Hosted by Sandra Tsing Loh
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Scared of the Dark

Are you afraid of the dark?

This is Sandra Tsing Loh with the Loh Down on Science, saying it's only human.

Light, it turns out, is hard wired into the experience of fear. So say psychologist Brian Wiltgen and colleagues at the University of Virginia, who modeled the effect of ambient light on learned fear in mice.

The researchers trained the mice by playing them a minute-long tone, followed by a quick shock to their little feet. Imagine you got hit with a taser every time the phone rang. Pretty soon you'd be cringing every time you heard that sound. That's "learned" as opposed to "instinctive" fear.

So what does light have to do with it? Well, when the researchers turned up the lights, mice cowered more and longer than they did when kept in the dark. Upshot: the light increased their learned fear.

Of course, in humans, the effect is likely reversed, with low light enhancing fear. The results could help in the treatment of a range of anxiety conditions including post-traumatic stress disorder.

In the meantime, people, no shame in clicking on that Donald Duck nightlight!

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