We studied the responses of neurons to stimulus movement: that generated by real motion in the environment, by saccadic eye movements, and by smooth pursuit eye movements. Cells in the pulvinar discharge to real movement during periods of fixation but not when a saccadic eye movement causes the visual stimulation. However, these same cells do respond to the visual stimulation induced with pursuit eye movements. Many of these cells have a pause in their activity when an animal makes eye movements in total darkness, and it may be this inhibitory process which prevents them from responding with eye movements in the light. Neurons in the lateral geniculate nucleus respond in all three conditions: during fixation and with both types of eye movements. Cells in the superior colliculus are similar to those in the pulvinar, they respond to real motion during fixation and with pursuit movements but not with saccadic eye movements. These data show that some parts of the brain are influenced by the behavioral context in which visual stimulation occurs whereas others are not. We tested other pulvinar cells for their excitability after saccadic eye movements. Many respond better to light just after an eye movement that during fixation. Such changes may be related to the analysis of new data with each change in eye position. Other pulvinar cells are very selective for the frequency of stroboscopic stimulation; they respond very strongly to pulses at 4 to 6 per second. Frequently, they respond better to later stimuli in a train than to the first stimulus. Cells in the lateral geniculate nucleus have a wide variety of temporal response patterns which encode the details of visual stimulus patterns. Normal humans respond faster to a visual target when its spatial location is correctly indicated by a cuing light than when the location is incorrectly cued. The hypothesis is that the cue draws attention to its location and thereby facilitates reaction times. Patients with progressive supranuclear palsy who cannot make vertical eye movements are nonetheless able to move their attention in that direction.
