Selective perception in probing by foot: Perceiving the length of a probe and the distance of a probed surface

Perception of properties of object wielded by means of muscular effort exhibits both task specificity and anatomical independence. A person can perceive different properties of an object wielded by a given anatomical component and can perceive a given property of an object wielded by different anatomical components. Task-specificity and anatomical independence are fundamental characteristics of the haptic system described a biotensegrity system embedded in lawfully structured energy arrays. We investigate whether both characteristics are also exhibited when a person attempts to perceive properties by means of a wielded object. Participants used a foot-wielded rod to probe a surface and reported the length of the rod and the distance of the surface probed (on separate sets of trials). The ability to differentiate these properties generalized across anatomical components, and perception of each property by foot was supported by sensitivities to the same invariant mechanical parameters that support perception of each property by hand. The results suggest that the biotensegrity hypothesis applies to perception both of and by means an object attached to the body.