Perception is the activity by which we pick up information about environmental objects and events. As Eleanor Gibson has pointed out, that information exists at several levels: Skilled perceivers make use of higher-order structure where infants and novices may have to depend on simpler features. In addition, perception is selective. The fact that a perceiver is capable of picking up a certain kind of information does not mean that she will do so in every case. We refer to this selectivity when we say that she attends to one or another subset of the information available. The terms perception and attention refer to different aspects of the same activity.