Abstract
Affordance perception is a forward-looking act of the opportunities of action offered by the environment and relative to individual capacities. This is exemplified by experienced rock climbers who must determine the task goal (use hold for support or facilitate movement) when balancing on one or both of their feet. The present study examined how the base of support (single and dual leg balance) and hold size affect an individual's ability to determine their maximum boundary of reach- and grasp-ability. The maximal boundary of reach-ability and grasp-ability was determined using a sliding assessment hold. Twenty participants (10 climbers and 10 non-climbers) provided verbal estimates of maximal reach to a big and a small hold while balancing on one or two feet. Perceptual accuracy differed depending on whether the objective was reach-ability or grasp-ability (p < 0.001). Neither standing on one or two feet, nor climbing expertise affected perceptual accuracy. The results suggest that the task goal (e.g., grasp-ability or reach-ability) affects the accuracy of perception of action boundaries.