Task constraints on affordance boundaries

Affordances are opportunities for action that exist between an organism and its environment (Gibson, 1979). The dimensionless, body-scaled ratios that are used to characterize this fit are known as pi-ratios (Warren, 1984). These pi-ratios have been used the demarcate affordances such as the step-on (Warren, 1984) and sit-on-ability (Mark, 1987) of surfaces of different heights, the pass-through-ability of apertures of different widths (Warren & Whang, 1987) and the reach- (Carello, Grosofsky, Reichel, & Solomon, 1989) and grasp-ability of different objects (Cesari, & Newell, 1999; Richardson, Marsh, & Baron, in press). The current study examined the role that different task constraints or demands, such as task speed or a non-relevant cognitive load, have on the perception of affordances and affordance boundaries.