David Eagleman: ‘The working of the brain resembles drug dealers in Albuquerque’ | Neuroscience | The Guardian

In what way does the working of the brain resemble drug dealers in Albuquerque?

It’s that the brain can accomplish remarkable things without any top-down control. If a child has half their brain removed in surgery, the functions of the brain will rewire themselves on to the remaining real estate. And so I use this example of drug dealers to point out that if suddenly in Albuquerque, where I happened to grow up, there was a terrific earthquake, and half the territory was lost, the drug dealers would rearrange themselves to control the remaining territory. It’s because each one has competition with his neighbours and they fight over whatever territory exists, as opposed to a top-down council meeting where the territory is distributed. And that’s really the way to understand the brain. It’s made up of billions of neurons, each of which is competing for its own territory.

The following paragraph is a new and different way of looking at why we dream:

One of the big surprises of neuroscience was to understand how rapidly these takeovers can happen. If you blindfold somebody for an hour, you can start to see changes where touch and hearing will start taking over the visual parts of the brain. So what I realised is, because the planet rotates into darkness, the visual system alone is at a disadvantage, which is to say, you can still smell and hear and touch and taste in the dark, but you can’t see any more. I realised this puts the visual system in danger of getting taken over every night. And dreams are the brain’s way of defending that territory. About every 90 minutes a great deal of random activity is smashed into the visual system. And because that’s our visual system, we experience it as a dream, we experience it visually. Evolutionarily, this is our way of defending ourselves against visual system takeover when the planet moves into darkness.

I am not sure I am buying that entirely because dreams seem to be so much more than just maintaining control of computing real estate. But, while dreams may have started out as exercising and maintaining the visual territory of the brain perhaps over time those dreams were coopted by other parts of the brain, in order to digest experiences and ideas during downtime/sleep.