The perception of surface roughness by active and passive touch

Subjects made magnitude estimates of the roughness of metal gratings by both active and passive touch (with object movement). The perceived magnitude of surface roughness and the consistency of such judgments were identical under the two modes of tactual examination. The results have implications for sensory physiology studies of the cutaneous peripheral mechanisms that underlie texture. They also question the prevailing notion in somethesis and tactual perception that active touch is always superior to passive touch.