WHEN YOU READ something confusing, or work a crossword puzzle, or try to remember where you put your keys, what do you do with your body? Do you sit? Do you stand? Do you pace? Do you do anything with your hands? Do you move your eyes in a particular pattern?

How you answer questions like these, it turns out, may determine how long it will take for you to decipher what you're reading, solve your puzzle, or get your keys back.