Tactile spatial resolution. III. A continuum mechanics model of skin predicting mechanoreceptor responses to bars, edges, and gratings

Abstract

A mechanistic model of skin is develooed to predict the state of stress and strain at mechanoreceptor terminals within the skin when any static stimulus having a defined spatial profile (e.g., a grating) is applied to the surface. The model is based on standard continuum mechanics theory. For small deformations the mechanical properties of skin are assumed to be adequately approximated by those of a homogeneous, elastic, isotropic medium. A central assumption is that the effect of a complex stimulus can be determined by decomposing it into simple subunits and then superimposing their effects. By recording single slowly adapting (SA) mechanoreceptor responses in monkeys to 2 independently controlled stimuli within the fibers'' receptive fields, it is shown that the principle of superposition may be considered to apply when the stimuli are defined by applied force but not displacement.