Affordance-Based Control of Visually Guided Action

The purpose of this essay is to compare and contrast existing theoretical approaches to understanding the visual guidance of action and to introduce a new approach. The focus is on tasks, such as steering, braking, and intercepting, that are (more or less) continuously guided on the basis of visual information. The prominent approach, information-based control, captures important aspects of behavior but is incompatible with the theory of affordances, a core principle of the ecological approach. Information-based control also fails to capture how actors behave in ways that take the limits of their action capabilities into account. I attempt to resolve these problems by introducing a new approach, affordance-based control, which asserts that a primary function of vision is to allow actors to see the world in terms of what they can and cannot do. Affordance-based control captures the tight coupling between information in optic flow and movement that is characteristic of visually guided action but also provides a parsimonious explanation of how actors take into account the dynamic properties of their body and the environment.