Differences in direction specificity of receptive fields in upper and lower layers of the cat's prestriate area 18

Direction specificity was measured for neurons in area 18 (A18) in penetrations approximately perpendicular to the layers in awake cats. A majority of lower layer cells (below 1.0 mm) preferred stimuli moving at rather orthogonal directions with respect to the preferred directions of the neurons in the upper layers (0-1.0 mm). The results suggest more functional autonomy of the corresponding cortical layers.