【英语时差8,16】眼睛快速扫视-下（在线收听）

During the fraction of a second that a saccade takes, images sweep over our retinas at high speed. Yet we don’t get a feeling of motion, because our brain suppresses visual perception during saccades. Otherwise, the world might look to us like a bad home video where the photographer held the “record” button down while swinging the camera around the room. An odd thing about this suppression is that it’s not complete. Get in the car and have someone drive you past a roadside fence. Without moving your head, glance quickly from front to back; you can make the fenceposts seem to freeze for an instant. Why, in this case, is vision not suppressed? A team of visual scientists published a study of this question in the journal Nature. They found that what gets suppressed during a saccade are large areas of light and dark. Those are the perceptions that seem to contribute the most to a sense of motion. Finer details, like fenceposts, are not suppressed, maybe because there’s no need to suppress them. Rapid eye motions usually turn them into a blur anyway.