IN “The Invisible Gorilla,” a book about what we see and what we think we see (it came out in paperback in June), two cognitive psychologists, Christopher Chabris and Daniel Simons, describe an experiment they performed with a chess grandmaster named Patrick Wolff. They briefly showed him a diagram of a chess position from an “obscure master game,” gave him a set of pieces and asked him to re-create the position on an empty board from memory. He did so almost perfectly and then repeated his performance.

“By recognizing familiar patterns,” they wrote, “he stuffed not one but several pieces into each of his memory slots.” Perhaps surprisingly, he couldn’t do the same with random arrangements on the board: “His memory was no better than that of a beginner, because his chess expertise and database of patterns were of little help.”

Recognizing patterns is part of the film critic’s tool kit along with a good pen to take notes in the dark. You have to take in a lot of information when you watch a movie just once. The easy stuff is usually the story (boy meets girl) and characters (Romeo and Juliet). The tricky part, when I get to scribbling, is everything else, including how the boy and girl met and what happened next. (That’s the plot.) Was the lighting soft or hard, the editing fast or slow, the camera shaky or smooth, the acting broad or not? Also: Did they dance like Fred and Ginger, shoot like Angelina and Brad? Was it a musical (but funny) or a comedy (with dancing)? Mostly, how does the narrative work?