Dolphin echolocation works differently in the brain than human echolocation, which, for those who learn the skill, is processed primarily in the visual cortex. To pinpoint the neural mechanisms behind the dolphin variety, the researchers compared preserved brains from three echolocating dolphin species with that of a sei whale, which is closely related but doesn’t echolocate. They measured the diffusion of water molecules along nerve fibers—like cars driving along a highway, as Marino puts it—to better understand which parts of the brain interact in living dolphins and in sei whales. Contrary to the earlier Russian research, there seemed to be nothing exceptional occurring in the dolphins’ visual cortex. Instead an entirely different stretch of neural highway caught the researchers’ attention: the one linking the inferior colliculus to the cerebellum. {read}