TEXTURE INFORMATION IN TACTUAL SPACE-PERCEPTION

The significance of texture as a source of information in tactual spac e perception was studied using a linear positioning task. A spatial te xture gradient, whose elements changed with position and distance, a h omogeneous raised-element pattern and a smooth surface were used. Part icipants had to reproduce locations and distances on these surfaces un der various conditions. In active conditions, participants moved their indexfinger across the surface. In passive conditions, the texture wa s moved beneath the indexfinger of the participant. In conditions with equal movement speed, movement speeds of criterion and reproduction p hase were matched, in conditions with unequal movement speed, they did not match. The largest errors were obtained for the combined passive movement-unequal movement speed conditions. In these conditions, diffe rences between textures were visible for signed and unsigned errors, i ndicating that textures may differ in the cutaneous specification of d istance and location. (C) 1998 Elsevier Science B.V. All rights reserv ed.