Two photos, one small change, and you stare for ages before you find it. The reason is that your visual system does not keep a copy of the picture. It keeps a summary of what things mean, and a change to a meaningful part of the scene is caught much faster than a change to a meaningless one.
Jump a film a full second forward during an eye movement and most people never notice. Jump it backward and they notice more often. Two studies on how vision papers over gaps in time, and why the direction matters.
Some people can follow six moving things at once and others lose track at three. The usual story blames a limited mind. A model that borrows each person's eye movements tells a simpler one.
