Realize that every human cell in your body, including your neurons, is a direct descendent of eukaryotic cells that lived and fended for themselves, for about a billion years, as free-swimming, free-living little agents. They had to develop an awful lot of know-how and self-protective talent to do that. But when they joined forces to become multi-cellular creatures, they gave up a lot of that. They became, in effect, domesticated — part of larger, more monolithic organizations.
In general, we don’t have to worry about our muscle cells rebelling against us. (When they do, we call it cancer.) But in the brain, I think, some little switch has been thrown in the genetics that, in effect, makes our neurons a little bit feral. It’s like what happens when you let sheep or pigs go feral: they recover their wild talents very fast.
Maybe the neurons in our brains are not just capable, but motivated, to be more adventurous, exploratory, or risky in the way they live their lives. They’re struggling amongst themselves for influence and for staying alive. As soon as that happens, you have room for cooperation, to create alliances, coalitions, cabals, etc.
Mike Merzenich sutured a monkey’s fingers together so that it didn’t need as much cortex to represent two separate individual digits, and pretty soon the cortical regions that were representing those two digits shrank, making that part of the cortex available to use for other things. When the sutures were removed, the cortical regions soon resumed pretty much their earlier dimensions.
Or if you blindfold yourself for eight weeks, as Alvaro Pascual-Leone does in his experiments, you find that your visual cortex starts getting adapted for Braille, for haptic perception, for touch.
Why should these idle neurons be so eager to pitch in? Well, they’re out of work. They’re unemployed, and if you’re unemployed, you’re not getting your neuromodulators, so your receptors are going to start disappearing, and pretty soon you’re going to be really out of work, and then you’re going to die.
Kevin Simler, One Brain, Many Selves: Demons, Tulpas, and Neurons Gone Wild, 2014