The Hour Between Dog and Wolf: How Risk Taking Transforms Us, Body and Mind

by John Coates

A fascinating example of this preconscious processing can be found in a phenomenon known as blindsight. It became a topic first of curiosity and then of medical concern during the First World War, when medics noticed that certain soldiers who had been blinded by a bullet or shell wound to the visual cortex (but whose eyes remained intact) were nonetheless ducking their heads when an object, such as a ball, was tossed over their heads. How could these blind soldiers “see”? They were seeing, it was later discovered, with a more primitive part of the brain. When light enters your eye its signal follows the pathways, described above, back to your visual cortex, a relatively new part of the brain. However, part of the signal also passes down through an area called the superior colliculus, which lies underneath the cortex, in the midbrain (see fig. 5). The superior colliculus is an ancient nucleus (collection of cells) that was formerly used for tracking objects, like insects or fast-moving prey, so that our reptilian ancestors could, say, zap it with their tongues.