AN ACCOUNT OF THE SYSTEMATIC-ERROR IN JUDGING WHAT IS REACHABLE

An account of the postural determinants of perceived reachability is p roposed to explain systematic overestimations of the distance at which an object is perceived to be reachable. In this account, these errors are due to a mapping of the limits of prehensile space onto a person' s perceived region of maximum stretchability, in the context of a whol e-body engagement. In support of this account, 6 experiments on the ju dged reachability of both static and dynamic objects are reported. We tentatively conclude that the mental imagery of action is grounded and calibrated in reference to multiple skeletal degrees of behavioral fr eedom. Accordingly, this calibration is a source of systematic error i n reachability judgments.