The Neural Control of Visually Guided Eye Movements

B. Subcortical Mechanisms of Visually Guided Saccadic Eye Movements

Figure 3 shows a temporal trace of vertical eye movements and the discharge of a neuron in the monkey oculomotor nucleus that innervates the inferior rectus. The maintained activity of the neuron during fixations is proportional to the angular deviation of the eye in orbit. Brief, high frequency bursts result in downward saccadic eye movements; the longer the burst, the larger the saccade. We refer to the coding operation here as a rate code.