Unless you’ve been hiding under a proverbial rock you’ve heard that 3-D – and the much-vaunted “immersive experience” it provides – represents the future of the movie-going enterprise. Avatar signaled the coming of the new age, of course, with its cutting-edge production and trippy visuals lifted from a 1970s progressive rock album cover (floating mountains! iridescent flora!). Audiences were enchanted, and studios rode this wave of delight with a spate of high-profiles releases. And interest in the format continues to build. This month has seen the release of Jackass 3D, for example, and news that George Lucas will be overhauling the entire Star Wars series, converting the films to 3-D and rereleasing them in sequence beginning in 2012. And many more movies will hit the screens before this year is out, including The Chronicles of Narnia: The Voyage of the Dawn Treader, Tron: Legacy and – get this! – Yogi Bear. I got to wondering the other day: What makes 3-D movies so exciting? What enables the so-called immersive experience the best of them provide? There’s the technology, of course – for instance, the circular polarization technology developed by RealD. Even beyond that, though: What is it about us, the viewers? Barry Sandrew, founder and president of Legend3D, a digital media technology company that converts 2-D content to 3-D, offers some insight. In a recent interview written up in the Hollywood trade Variety, Sandrew – a trained neuroscientist who established several labs at Harvard Medical School in the 1970s and ‘80s, including one focusing on MRI, CAT and PET imaging of the brain – described research demonstrating how 3-D movies affect viewers differently than traditional, 2-D movies. The stereo vision of 3-D movies, he said, reflects the “binocular disparity” we experience naturally when viewing objects with two eyes. So when an object flies toward the camera we react to it as we would in real life. The stereo vision activates a particular pathway in our brain, thus stimulating the amygdala, which plays an important role in emotional behavior – especially in anger and fear. In other words, afraid of getting whacked in the face, we duck. At the same time, the use of stereo cameras enables a more intimate, dare I say more immersive viewing experience. And it is this to which audiences are responding with today’s 3-D movies. “Disparity is something the brain is expecting,” Sandrew said. “It's closer to reality, so it has a deeper meaning, a more significant meaning to the observer.”