“About one-third of the human brain is devoted to vision,” writes neuroscientist David Eagleman in his bestselling book on the brain Incognito: The Secret Lives of the Brain. So when a blind person stops receiving visual input from their eyes, their brain-power can be reprogrammed to receive it in another way.
Visual-tactile substitution glasses can take the visual input from a camera and translate it into vibrations on a pad on the person’s back. After about a week, blind users of the device “become quite good at navigating a new environment.” They actually begin to perceive the pressure on their backs as sight: “The apparatus reminds us that we see not with our eyes but rather with our brains.”
In Eagleman’s telling, there is no conscious learning how visual-tactile substitution works. There is no memorizing certain patterns that equate to visual descriptions of the environment. Instead, the brain simply figures it out. In his book Strangers to Ourselves, Timothy Wilson writes that our brain processes as much as 11 million pieces of information per second, while only 40 bits enter consciousness.
If we think of ourselves only in terms of what enters our consciousness—even if that is the most important—then we fail to understand much of who we are. As the head of Baylor’s Laboratory for Perception and Action, Eagleman is at the forefront of efforts to revise our understanding of human nature. For the last 20 years, technological advances have allowed scientists to be able to watch the brain at work. We’ve seen that many of the functions we ascribe to our core selves are dependent upon brain functions. We’re realizing how dependent our sense of ourselves is on our biology and its interaction with the environment, and we’re seeing how enmeshed we are with our friends and family, parents and grandparents, as well as our culture and faith.
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