Neural mechanisms of tactual form and texture discrimination.

The mechanisms of fine form discrimination and texture discrimination are discussed in terms of a set of working hypotheses. 1) The limits of fine form discrimination at the fingertips are set by peripheral, not central, factors. 2) The critical information is relayed by slowly adapting (SA) afferents. 3) Texture is coded by the relative discharge rates in the quickly adapting, Pacinian, and SA populations. 4) SA transduction and transmission properties are particularly adapted for signaling spatial information. 5) The skin of the finger pad behaves like an ideal continuous medium.