Spatial properties of receptive fields of mechanosensitive primary afferent nerve fibers.

Tactile sensation is rich and varied, requiring input from a variety of mechanoreceptors whose spatiotemporal aspects deserve careful study. Recent data for virtually every class of sensitive mechanoreceptor have revealed spatial inhomogeneities in sensitivity reflecting the distribution of sense organ terminals and the complexity of gradients in the complex spatial organization of receptive fields. Controlled surface parallel stimulation provides a means for examining sensitivity in a manner that may shed light on active tactile exploration and allow quantitative analysis of orientation, direction, and velocity properties underlying some aspects of feature extraction by the central nervous system.