Incorporating the properties of peripheral vision into theories of visual search

People often look for objects in their immediate environment, a behaviour known as visual search. Most of the visual signals used during search come from peripheral vision, outside the direct focus of the eyes. In this Review, we present evidence that peripheral vision is both more capable and more complex than commonly believed. We then use three benchmark findings from the visual search literature to illustrate how considering peripheral vision can improve understanding of the basic mechanisms of search. Next, we discuss theories of visual search on the basis of their treatment of peripheral processing constraints and present findings in support of theories that integrate the characteristics of peripheral vision. These findings describe the span over which peripheral vision can extract useful information, the type of information peripheral vision encodes, and how peripheral vision identifies locations that are likely to contain a search target. We end by discussing considerations for future theoretical development and recommendations for future empirical research.