Laminar distribution of preferred orientations in foveal striate cortex of the monkey.

Microelectrode penetrations normal to the layers of foveal striate cortex in awake, behaving monkeys have revealed two new facts about the distribution of orientation preferences in this tissue: (1) In the top layers there is a predominance of vertical orientation preferences at eccentricities of less than 30 min, and a predominance of oblique orientation preferences at eccentricities of 30 min to 2 deg. (2) At all eccentricities between 0 and 2 deg there is a striking difference in orientation preference between upper layer (supragranular) and lower layer (infragranular) cells.