Coding of Object Shape and Texture

While much is known about the peripheral afferent systems that underlie somatic sensation, little is known about how information from those systems leads to the perception of shape and texture. Emerging evidence suggests that the pathway for object and texture perception progresses from the peripheral afferents through the dorsal column nuclei and ventroposterior lateral nucleus of the thalamus to primary and then to secondary somatosensory cortex where cutaneous and proprioceptive inputs from the skin, muscles and joints are integrated to produce central representations of the 3D structure of objects. The cutaneous inputs provide information about the local spatial structure and texture of the surface at the points of contact between the skin and object. The proprioceptive inputs provide information of where those contact points lie in 3D space. A working hypothesis is that the cutaneous and proprioceptive inputs are integrated in cortex to form central representations of objects that are matched against memory and perception.