Figure 10.

Spatial processing in the somatosensory system. (A) Reconstructed response of tactile nerve fibers to embossed letters scanned across the skin. As in the retina, the spatial configuration of the stimulus is reflected in the spatial pattern of activation it evokes in SA1 and RA populations. Reproduced, with permission, from (282). (A) Responses of a neuron in area 3b to oriented edges indented into the skin (eight orientations, three indentation depths). This neuron is strongly tuned for edge orientation, as are neurons in primary visual cortex. Reproduced, with permission, from (11). (C) Responses of an LPC neuron to curvatures indented into the skin. This neuron prefers intermediate curvatures with the convex end pointing proximally. This type of feature selectivity is not observed in early stages of cortical processing (e.g., in area 3b). Reproduced, with permission, from (391). (D) Responses of an LPC neuron to bars indented into the skin. This neuron exhibits the similar preferred orientation over large swaths of skin (position-invariant orientation tuning). Reproduced, with permission, from (107).