Tactile roughness of grooved surfaces: The touching process and effects of macro- and microsurface structure

Abstract

Ss made magnitude estimates of the perceived roughness of grooved aluminum plates. Two aspects of the touching process were altered and their effects upon roughness examined. Roughness increased with increasing finger force, regardless of whether the S or the E chose the values. Rate of hand motion had a negligible effect on perceived roughness, indicating a roughness constancy and providing further evidence of the relative unimportance of vibratory frequency. The effects of these components of the touching process were discussed in terms of an active-passive continuum rather than a dichotomy. Perceived roughness declined with increasing land width (with narrow grooves), although only over the widest half of the land range; there was no land effect when the grooves were wide. In addition to these macrostructural parameters, the effects of two stimulus production techniques were compared. The discrepancies between the two sets of data were interpreted in terms of the microscopic irregularities of the plate surfaces. The findings were briefly related to an analysis of perceived roughness of grooved surfaces in terms of static deformation of the skin. © 1974 Psychonomic Society, Inc.