Receptive fields of single neurones in the cat's striate cortex.

Also: Hubel & Wiesel, Receptive fields, binocular interaction and functional architecture in the cat's visual cortex, J. Physiol., 160, 1962, 106-154. 

In 1981 Hubel and Wiesel shared half of the Nobel Prize in Physiology or Medicine for “for their discoveries concerning information processing in the visual system.” The other half was awarded to Roger W. Sperry "for his discoveries concerning the functional specialization of the cerebral hemispheres."