Zombie 'rush': Why fake scares are so much fun It's dark. Suddenly, someone -- or something -- lurches forward, grabbing you with a decaying hand. A scream erupts from your throat, but then you realize this zombie isn't part of the apocalypse; it's just an actor at the local haunted house. Haunted houses like the House of Shock in New Orleans are getting even more elaborate and more popular. It's a safe thrill, experts say. Every Halloween, scores of people watch bloody monster movies or trek through haunted houses all to scream like a little child. What possesses people to seek horror movies and haunted houses? "It is a safe way to trigger an arousal response and some people find that pleasurable and enjoyable - and some people find it annoying," explains Joseph LeDoux, a professor at the Center for Neural Science at the Emotional Brain Institute at New York University. It's not the haunted house itself, it's what you experience and what you bring to that and how you can interpret it cognitively. Horror movies, often referred to as torture porn, and haunted houses are becoming more and more terrifying. Blackout Haunted House in New York and Los Angeles requires patrons to sign waivers - and everyone walks through the house alone. Patrons receive a safety word that they can shout out if the tour becomes too horrific. LeDoux studies how the brain processes fear. When a door creaks loudly, the body reacts. The brainstem triggers a startle response, heighted alertness, which could lead to jumping or freezing to protect yourself (you also blink more to shield your eyes). "The startle is caused by a sudden stimulus not because it is scary because it is rapid and quite loud," LeDoux says. Because the brainstem, not a higher functioning part of the brain, controls this, most startle responses are purely reflexive. Then the amygdala spurs fixed body actions, more complicated movements that enable people to deal with dangerous situations. Finally, your voluntary responses kick in - when you choose to run away or hide from the saw-wielding surgeon. "You're going to put yourself in the situation where the goal is to activate your bodily responses," he says. And all these responses cause arousal. Basically, watching a horror flick or wandering through a haunted house provides a rush. Frank Farley, a psychology professor at Temple University, agrees, adding that it is humans" fascination with macabre that drives people to scare themselves. "Throughout our history we have been enamored by the dark side," he says. For some, watching a gory movie or going to a haunted house helps them explore the horrors that occur in life. Zombies remain ubiquitous, Farley suspects, because they embody humans" fear of death - and the unknown - as well as exploiting the horror of life. The reanimated corpses just continue coming after victims, no matter what happens. Ultimately, wanting to be scared provides an accessible thrill. So few people will jump from a capsule in space or even leap off a cliff and scary movies and spooky attractions give everyone a chance to feel the high. "Basically, you are getting a rush of physiology," LeDoux says.