Reconsidering the role of movement in perceiving action-scaled affordances.

Many locomotor tasks require actors to choose among different categories of action, such as when deciding whether to cross the street in front of an approaching vehicle or wait until it passes. In such cases, the actor's locomotor capabilities partly determine which actions are possible, and therefore must be taken into account. The present study was designed to re-evaluate the claim that people do not know their locomotor capabilities until they begin moving because they rely entirely on information that is picked up "on the fly" (Oudejans, Michaels, Bakker, & Dolné, 1996). Three experiments were conducted in which participants judged while stationary or moving whether it was within their capabilities to catch a fly ball or pass through a shrinking gap. The main finding was that judgments were equally accurate regardless of whether participants were stationary or allowed to move for a brief period. We conclude that stationary and moving actors know their locomotor capabilities equally well, and that actors do not rely entirely on information that is picked up on the fly.