After the injection of 
deoxyglucose, the visual fields 
of the anesthetized monkey 
were stimulated with slowly 
moving vertical black and 
white stripes. The resulting 
autoradiograph shows dense 
periodic labeling, for example 
in layers 5 and 6 (large central 
elongated area). The dark gray 
narrow ring outside this, layer 
4Cß, is uniformly labeled, as 
expected, because the cells are 
not orientation selective.

The pattern we obtained, as 
shown in the autoradiograph to 
the left, was far more complex 
than that of ocular-dominance 
columns. Nevertheless the 
periodicity was clear, with 1 
millimeter or less from one 
dense region to the next, as 
would be expected from the 
physiology--the distance an 
electrode has to move to go from 
a given orientation, such as 
vertical, through all 
intermediates and back to 
vertical. Some places showed 
stripelike regularity extending 
for several square millimeters. 
We had wondered whether the 
orientation slabs and the 
ocular-dominance stripes 
might in any way be related in 
their geometry--for example, be 
parallel or intersect at 90 
degrees. In the same 
experiment, we were able to 
reveal the ocular-dominance 
columns by injecting the eye 
with a radioactive amino acid 
and to look at the same block of 
tissue by the two methods, as 
shown in the second 
autoradiograph to the left.