Perception of Tangential Displacements of Finger Print Skin

We are investigating how humans perceive tangential displacements (t) of finger print skin. Subjects adjust tangential displacement of a probe (p) to match perceived intensity of a normal indentation (n). In many directions (white regions of polygons) subjects find small tangential displacements as intense as the larger normal displacement. Gray circles indicate the amplitude of the normal stimulus. Initial results show tangential displacements often stimulate finger skin as as well as or better than normal displacements. This finding may facilitate the design of tactile displays.