To determine if electrically stimulating a part of the brain known as the lateral geniculate nucleus (LGN) could be used to enhance vision, scientists trained two primates with electrodes implanted in their LGNs to move their eyes toward a white dot as it appeared on a computer screen. The scientists then tracked the animals' eye movements as they alternately flashed a white dot on the screen and stimulated part of the LGN linked to a specific part of the visual world. In this animation, the animal's eye position is shown as a blue dot. White dots represent either an actual flash on the screen (labelled “normal”) or an "artificial" point, simulated by a jolt of electricity delivered to the part of the LGN that responds to that point of the visual field (labelled “artificial”). The animal moves its eyes toward the artificial points, suggesting that it "saw" a white dot in that location.