Studies aimed at the first issue have provided a relatively complete, basic description of the neural mechanisms underlying tactile perception. Form and texture perception are accounted for by the population response of Merkel receptors and their afferent fibers.
Motion perception is accounted for by Meissner receptors.
Transmitted vibration of the kindwe depend on when we use a tool or a manual probe is transduced by Pacinian receptors. Evidence for the role of the fourth type of mechanoreceptor is less certain but a role in the perception of hand shape has been suggested. These questions are being addressed with a new stimulator with 400 independently controlled tactile probes. The same kinds of combined psychophysical and neurophysiological studies that have worked so successfully in elucidating the basic mechanisms are now being used in studies of the cortex. Velocity invariance of receptive field structure in somatosensory cortical area 3b of the alert monkey.