Abstract

Tools do not just expand our capabilities. They change what we can do, and in doing so, they change who we are. Serena is Serena because of what she can do with a tennis racket. Tiger is Tiger because of what he can do with a golf club. In changing what we can do, tools also change the very way we perceive the spatial layout of the world. Objects beyond arm's reach appear closer when we wield a tool that can expand out to the object. Catchable objects seem to move faster when we wield a tool that is less effective for catching the object. These examples illustrate how the basic processes of spatial vision are impacted by tool use.