The perception and cognition of environmental distance: Direct sources of information

Research on direct sources of information for the perception and cognition of environmental distance is reviewed. Environmental distances are relatively large and cannot be perceived in entirety from a single place.Directly-acquired knowledge of environmental distance is based on the sensorimotor apprehension of information fromthe body or from the environment during locomotion. The paper is organized around the idea that distance knowledge is derived from multiple, partially redundant information sources. After briefly discussing general issues, I review literature on direct sources of distance information,including environmental features, travel time, and travel effort. Theories of how these sources provide information about distance are considered. To date, only information from environmental features has received much empirical support as a direct source of distance knowledge, particularly to the extent that the features segment routes into vistas. Key weaknesses in the empirical literatureare discussed, and importantresearch directions are identified.