why difficult movies are more, Um, difficult.

The experiment that gives “The Invisible Gorilla” its title reveals something about how much we see and don’t. More than a decade ago Professors Chabris and Simons made a short film in which players passed around basketballs. They then asked viewers silently to count the number of passes made by the players in white and ignore those made by the players in black. That sounds unremarkable except that about midway through, a woman in a gorilla suit walked in, faced the camera and pounded her chest before exiting. She was on the scene for nine whopping seconds but only about half the people watching the video saw the gorilla: they expected to see the players passing the ball, and that’s all they saw.

“We think we should see anything in front of us,” Professors Chabris and Simons write, “but in fact we are aware of only a small portion of our visual world at any moment.”

The viewers who didn’t see the gorilla suit made an error in perception that psychologists call “inattentional blindness.” As the professors write, “When people devote their attention to a particular area or aspect of their visual world, they tend not to notice unexpected objects, even when those unexpected objects are salient, potentially important and appear right where they are looking.” We are, they write, subject to all kinds of everyday illusions, including those produced by another phenomenon, “change blindness.” This is when you don’t notice obvious changes, like continuity flubs. Professors Chabris and Simons even quote a script supervisor, who despite her profession doesn’t always notice such errors when she’s watching a film because “the more into the story I am, the less I notice things that are out of continuity.”

The stronger the pull a narrative has on us, the more we’re hooked. If we don’t notice some disruptions — like the crew member wearing shades on deck near Johnny Depp in the first “Pirates of the Caribbean” movie — it’s probably because we’re busy following the action or watching Mr. Depp’s face. (We’re hard-wired to respond to faces.) Filmmakers use numerous strategies to keep us watching. As Mr. Bordwell recently wrote on his blog,davidbordwell.net, “perceptually, films are illusions, not reality; cognitively, they are not the blooming, buzzing confusion of life but rather simplified ensembles of elements, designed to be understood.” Both the real world and earlier movies we’ve seen teach us how to look at films: we look at movies and understand them through their norms.

via NYT and YMFY