Extracellular recordings were carried out in the primary visual cortex of behaving monkeys. Neurons were activated by moving a visual stimulus on their receptive fields during periods of steady fixation and by moving their receptive fields (smooth pursuit eye movements) on a motionless visual stimulus. Regarding non-oriented cells, they turned out to be activated by the visual stimulation both during steady fixations and smooth pursuit eye movements. Therefore, the non-oriented cells we studied seem not to receive an extraretinal signal related to the slow eye movements.
