In the present investigation, single unit responses in the visual areas 17 and 18 of the cat cerebral cortex were obtained by luminous stimuli sweeping the receptive field of cortical neurons at different velocities. Extracellular recordings were made by tungsten microelectrodes driven into the cortex through a closed chamber, chronically implanted at occipital sites. Steady conditions of autonomic functions of the animal were continuously checked for long-lasting (3-10 hrs) recordings from the same unit. More than 100 cells were analyzed and it was observed that both visual areas contain cells specifically sensitive to motion. The preferred velocities for striate neurons have a range which is much lower than that for cells in area 18; the two visual areas might be concerned with the control of some features of eye motility, probably different in the two areas. Finally, attention should be paid to the fact that the cell firing is much more easily elicited by luminous stimuli in area 17 and by dark images in area 18.
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Con il contributo del Ministero per i Beni e le Attività Culturali