Spatial and temporal codes mediate the tactile perception of natural textures

TLDR

Our exquisite tactile sensitivity to surface texture allows us to distinguish silk from satin or even good silk from cheap silk. We show that the tactile perception of natural textures relies on two neural mechanisms. Coarse textural features are encoded by spatial activation patterns in a dense fingertip mechanoreceptor population, while fine features are conveyed through vibration‑induced temporal patterns in two vibration‑sensitive afferent populations whose spiking activity shapes texture perception.

Abstract

Significance Our exquisite tactile sensitivity to surface texture allows us to distinguish silk from satin or even good silk from cheap silk. We show that the tactile perception of natural textures relies on two neural mechanisms. Coarse textural features, for example, the individual elements of Braille, are represented in spatial patterns of activation across one population of mechanoreceptive afferents that densely innervate the fingertip skin. In contrast, our ability to discern fine textural features is mediated by the transduction and processing of vibrations produced in the skin during scanning. Indeed, two other populations of vibration-sensitive afferents produce temporally patterned responses to these vibrations, and spiking patterns in these afferent populations convey texture information and shape the way textures are perceived.