Effects of Mass Loading and Arm-Movement Duration on Kinesthetic-Visual Intersensory Form Discrimination

Abstract

To determine the effects of mass loading of the active arm and arm-movement duration for the tracing of a kinesthetic stimulus on kinesthetic-visual intersensory form discrimination, 171 right-handed male undergraduate subjects judged kinesthetic arcs with reference to simultaneously perceived visual arcs, in terms of relative amount of curvature, under conditions of 100-, 1,158-, and 2,216-gm. loads and 1-sec, 5-sec, and 9-sec. durations in a 3 × 3 nonrepeated-measures design. The number of “incorrect” judgments showed that the greater loads improved discrimination when movement was of intermediate or long duration. Movement of short duration improved discrimination under minimum load. Discrimination was best with maximum load and intermediate duration and poorest with minimum load and long duration. It was concluded that intersensory discrimination can be improved by optimizing the conditions which affect intrasensory discrimination. The results were interpreted in terms of the augmentation of both attention and kinesthetic information.