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The average American watches five hours of television a day. A day. Subtract the time you'll spend sleeping and using the bathroom, and that means you'll pass close to a third of your waking life in front of the tube. How can one activity be so remarkably, consistently arresting? Like a perfectly addictive drug, almost every aspect of the television viewing experience grabs and holds your brain's attention, which explains why it's so tough to stop watching after just one (or three) episodes of Orange is the New Black.

When You Switch On the TV

Press power, and your room fills with new and constantly shifting patterns of light and sound. Camera angles pivot. Characters run or shout or shoot accompanied by sound effects and music. No two moments are quite alike. To your brain, this kind of continuously morphing sensory stimulation is pretty much impossible to ignore, explains Robert F. Potter, Ph.D., director of the Institute for Communication Research at Indiana University.

Potter blames a mind mechanism he and other researchers call the orienting response. "Our brains are hardwired to automatically pay attention to anything that's new in our environment, at least for a brief period of time," he explains. And it's not just humans; all animals evolved this way in order to spot potential threats, food sources, or reproductive opportunities, Potter says.

Your brain has the power to almost instantaneously identify and disregard new light or sound. But as soon as the music changes or the camera angle shifts, TV grabs your brain's attention again, Potter says. "I tell my students that if they think they can study in front of the TV, they're wrong," he jokes, adding that the constant stream of small interruptions will foil their attempts to concentrate on study materials. "This also explains how you can sit in front of the TV and binge for hours and hours at a time and not feel a loss of entertainment," he says. "You brain doesn't have much time to grow bored."

After 30 Minutes

Studies show that, by this point, most of your brain activity has shifted from the left hemisphere to the right, or from the areas involved with logical thought to those involved with emotion. There has also been a release of natural, relaxing opiates called endorphins, research indicates. These feel-good brain chemicals flow during almost any addictive, habit-forming behavior, and they continue to flood your brain as long as your watching television, suggests a study from the Journal of Advertising Research.

Endorphins also trigger a state of relaxation, the research shows. Your heart rate and breathing become calm, and, as time passes, your neurological activity shifts lower and lower into what scientists sometimes call your "reptilian brain." Basically, you're in a purely reactive state, these studies suggest. You're noodle isn't really analyzing or picking apart the data it's receiving. It's basically just absorbing. Potter calls this "automatic attention." He says, "The television is just washing over you and your brain is marinating in the changes of sensory stimuli."

After a Few Hours

Along with your automatic attention, you have a second type Potter calls controlled attention. This type involves a little more interaction on your brain's part, and tends to occur when you're watching a character or scene that's really interesting. "Attention is a continuum, and you're constantly sliding along that continuum between these controlled and automatic states," Potter explains.

At the same time, the content of your television show is lighting up your brain's approach and avoid systems, Potter says. Put simply, your brain is pre-programmed for both attraction and disgust, and both grab and hold your attention in similar ways. Characters you hate keep you engaged just as much (and sometimes more) than characters you love. Both of these systems reside in part in your brain's amygdala, Potter explains.

After You (Finally!) Turn Off the TV

Like any addictive drug, cutting off your supply triggers a sudden drop in the release of those feel-good brain chemicals, which can leave you with a sense of sadness and a lack of energy, research shows. Experiments from the 1970s found that asking people to give up TV for a month actually triggered depression and the sense that the participants had "lost a friend." And that was before Netflix!

Potter says your emotional reactions to the content you were watching also linger for minutes or hours. If you're feeling angry or freaked out, those emotions could affect your interactions with your friends and family-maybe a case for sticking with the Mindys and Zooeys, and avoiding those Walter Whites.