Affordances and events

Affordance is a fundamental concept in the ecological approach to perceptio n and action, but it is not yet fully developed. In this article, I attempt to further the development of the concept by contrasting it with the conce pt of events. My specific purpose is to raise for further discussion the fo llowing question: Can a theory that predicts the perception of affordances also predict the perception of events! I argue that affordances and events are not identical and that they differ qualitatively. I also discuss what I call mutuality relations between the animal and its environment, which hav e inspired much research on perception-action couplings (e.g., the percepti on and control of interceptive action, or the guidance of locomotion). Ther e has been little direct discussion of relations between perception-action coupling and affordances. I suggest that mutuality relations are not afford ances and that they may be a category of events. As an example of this argu ment, I reinterpret common analyses of time-to-contact in terms of affordan ces for interceptive action. I argue that the utility of affordance percept ion is clear but that it is uncertain how an ecological theory could predic t the perception of events. I conclude with a brief discussion of some addi tional issues that remain to be resolved in the concept of affordances.