Neuroscientist Jeffrey Zacks says that filmmakers know a lot about how brains work, even if they couldn’t explain the science. After all, they’re able to get people to pay good money to watch light flickering on a screen, and they can get these people frightened, sad, jubilant in the space of a couple of hours. 

Zacks’s Flicker explains how it works by showing how movies make use of everyday mental processes. Part I of Zacks’s book examines the experience of moving watching, while the second part looks at the ways things that happen “outside our awareness” help “to produce the rich illusions we experience when watching films.”

We are all mimics, for instance. Zacks sites studies that show how people imitate the gestures, tone of voice, accent, and pace of speech to match that of a conversation partner. Social, mimetic beings that we are, we mimic the gigantic faces on the movie screen, and we react to action on film the way we would to other people. Movie-watchers tend to mimic the facial expressions of characters on screen, and that is one of the main ways moviemakers control emotion. We laugh with those who laugh, weep with those who weep. We duck when Rocky throws a punch our way.

Zacks also points to the “success effect.” The last time a cannonball came barreling toward you, your probably ducked and escaped injury. Success in one instance helps us develop habits of survival and escape, and we don’t leave those habits behind when we step into the theater. So when something appears to come rolling our way across the screen, we react as if we would if it were really rolling into our laps.

Fortunately, explaining isn’t the same as explaining away. Zacks doesn’t want to remove the magic of film. I’ll bet he still ducks and smiles mirroringly to the onscreen smile.