Fig. 5.

Nonuniform representation of direction within different regions of the L and the M hair direction maps. Eachpoint is the average magnitude of all directional vectors that are tuned to the same direction at that point in the map (shown on the x-axis). Directional tuning is represented with respect to body coordinates. There are five locations within the L direction map (dotted line) that have a greater magnitude compared with the rest of the map (data modified from Jacobs and Theunissen, 1996). Similar nonuniformity is seen for the M direction map (solid line). There are six locations in this map that have larger terminal density compared with the rest of the map. The peak density for the M afferents, in general, is much less than for the L afferents.