Writers and directors know this, too, and they exploit it. Charlie Lyne investigated how they capitalize on our biological reactions for his own film Fear Itself (via The Independent), and found horror movies are using plenty of tricks to get a very visceral response out of all your senses. Setting so many scenes during a dark and stormy night isn't just for atmosphere. The on-screen darkness actually makes your eyes move faster and amplify movement to make up for the color you can't see. When you do get color in horror movies, it's often red, for the simple reason it makes human brains uncomfortable. Sounds are the other big one, and Lyne says aside from the startling sounds (like horns and screechy music) you're aware of, some directors have started layering in low-frequency sounds just off our auditory range. You can't hear it, but you can feel it — and that's even worse.
