Wednesday, July 23, 2008

Neuroscience: How complex is your brain? More than you can easily imagine!

A friend writes to quote me a passage from Daniel Levitin's This Is Your Brain On Music, noting, "Levitin does a great job of presenting the complexity of the human mind, as relates to thought and music processing, in a way that even the non-specialist can understand":
It is difficult to appreciate the complexity of the brain because the numbers are so huge they go well beyond our everyday experience (unless you are a cosmologist). The average brain consists of one hundred billion (100,000,000,000) neurons. Suppose each neuron was one dollar, and you stood on a street corner trying to give dollars away to people as they passed by, as fast as you could hand them out- let's say one dollar per second. If you did this twenty-four hours a day, 365 days a year, without stopping, and if you had started on the day that Jesus was born, you would by the present day only have gone through about two thirds of your money. Even if you gave away hundred-dollar bills once a second, it would take you thirty-two years to pass them all out. This is a lot of neurons, but the real power and complexity of the brain (and of thought) comes through their connections.

Each neuron is connected to other neurons- usually one thousand to ten thousand others. Just four neurons can be connected in sixty-three ways, or not at all, for a total of sixty-four possibilities. As the number of neurons increases, the number of possible connections grows exponentially...The number of combinations becomes so large that it is unlikely we will ever understand all the possible connections in the brain, or what they mean. The number of combinations possible- and hence the number of possible different thoughts or brain states each of us can have- exceeds the number of known particles in the entire known universe." (Levitin, pp.85-86)
Yes, we take good note of that in The Spiritual Brain. Most of us, far from overestimating our brains, probably underestimate them. It's not magic, but it is reality. It will not do everything we want, but it will do far more than we sometimes expect.