Mutuality in the perception of affordances and the control of movement.

James Gibson introduced the concept of affordance to emphasize the importance of behavior in constraining perception. In this view, perception is not judged in terms of sensitivities to properties that are measured by physical instruments (photometers for brightness, scales for weight, etc.) but in terms of properties that matter to behaving systems (whether an object is appropriate to carry out some task). The affordance notion is brought to bear on understanding and motivating a variety of experimental phenomena in the study of dynamic touch, the domain of touch most concerned with using objects and interacting with surfaces.