Mechano-neurophysiological model of the fingertip for spatiotemporal firing pattern prediction of SA1 mechanoreceptors during embossed letter scanning

Abstract

Numerical simulation can be used to observe spatiotemporal firing responses of tactile receptors during dynamic tactile exploration, and it provides a more understanding of the mechanism of tactile perception. In this study, we developed an improved mechano-neurophysiological model of the fingertip that employs a realistic fingertip structure and accurate contact mechanics while scanning embossed letters. To confirm the potential of the model, we simulated the spatiotemporal firing patterns of slowly adapting type-1 (SA1) mechanoreceptors while scanning the embossed letter “G” and compared the simulation result with the existing experimental data in neurophysiology. Although the experimental data were reconstructed from a single nerve fiber, the simulation simultaneously observed the responses of multiple SA1 receptors, which resulted in a more obscure “G” spatiotemporal firing pattern than that in the previous experiment. This result supports existing data from another psychophysical experiment that demonstrates that it is harder to recognize embossed letter “G” accurately during letter scanning. This finding suggests that the spatiotemporal firing pattern from multiple SA1 receptors may show an obscure “G” pattern while scanning the embossed letter “G”.