Changing action capabilities and the perception of affordances

Specification of the relevant properties of environment and actor enables the perception of affordances. In the present paper it is emphasised that affordances are dynamic and that to accurately perceive affordances the relevant geometric and kinetic properties of the Environment-Actor System (EAS) have to be perceived. The reach-with-jump action is used to test whether participants are able to perceive the kinetically defined boundaries for overhead reaching. In three experiments actor and environmental components of the EAS for reaching are manipulated. Data reveal that participants are able to identify the boundary that separates a reachable from an out-of-reach ball, in different mass and ground surface conditions. It is concluded that when the dynamics of the EAS for reaching are altered, perception of the limits of prehensile space changes accordingly.