02143nas a2200229 4500008004100000245007100041210006700112260001200179300001600191490000700207520149200214653001201706653001301718100001901731700001601750700001401766700001701780700001601797700001401813700001501827856007101842 2016 eng d00aThe Change in Fingertip Contact Area as a Novel Proprioceptive Cue0 aChange in Fingertip Contact Area as a Novel Proprioceptive Cue c05/2016 a1159–11630 v263 a
Humans, many animals, and certain robotic hands have deformable fingertip pads. Deformable pads have the advantage of conforming to the objects that are being touched, ensuring a stable grasp for a large range of forces and shapes. Pad deformations change with finger displacements during touch. Pushing a finger against an external surface typically provokes an increase of the gross contact area, potentially providing a relative motion cue, a situation comparable to looming in vision. The rate of increase of the area of contact also depends on the compliance of the object. Because objects normally do not suddenly change compliance, participants may interpret an artificially induced variation in compliance, which coincides with a change in the gross contact area, as a change in finger displacement, and consequently they may misestimate their finger’s position relative to the touched object. To test this, we asked participants to compare the perceived displacements of their finger while contacting an object varying pseudo-randomly in compliance from trial to trial. Results indicate a bias in the perception of finger displacement induced by the change in compliance, hence in contact area, indicating that participants interpreted the altered cutaneous input as a cue to proprioception. This situation highlights the capacity of the brain to take advantage of knowledge of the mechanical properties of the body and of the external environment.
10aHaptics10aRobotics1 aMoscatelli, A.1 aBianchi, M.1 aSerio, A.1 aTerekhov, A.1 aHayward, V.1 aErnst, M.1 aBicchi, A. uhttp://www.sciencedirect.com/science/article/pii/S0960982216301348