Woo Alert! The Brain Science Podcast, Episode 44: Meditation and the Brain

Ginger's guest in this episode is Daniel Siegel, MD, author of The Mindful Brain. He is looking at how the experiences of meditation map onto the hardware of the brain, and what we can learn from such a mapping.

This is another great podcast from Ginger, but right at the end Siegel lapses into a poetic fit of 'WOO'.

The brain is an infinite space, he tells us. It has one hundred billion neurons, each with an average of 10,000 connections. The potential combinations of neurons x connections are so huge that if we started trying each combination out from birth we couldn't live long enough to experience them all, therefore, the brain is effectively infinite and aren't we awesome!

I've heard this 'WOO' before. Someone on a philosophy forum quoted these numbers at me and claimed there were more connections in a brain than there were particles in the Universe and, therefore, 'Woo, the brain is vast enough to hold the entire Universe in itself!'

Neurons in the brain: 100,000,000,000 = 10^11
Connections per neuron: 10,000 = 10^4
Total connections: 10^15

That looks like a hell of a big number, but it's easily beaten by, say, two brains.

Okay, that's an easy way to beat that number, but the real WOO comes in when the WOO-vulnerable contemplate the number of permutations possible with the two input numbers, i.e. (10^15)! That's (10^15)x(10^15 - 1)x(10^15 - 2)... etc. Now that's a seriously big number. I mean, it's bigger than the number of particles in the universe, isn't it?

Hmm, the trouble is that brains don't work like that. To see why, consider this little thought experiment.

Professor Woo has developed a demorphologizer. This is a cunning device for teasing apart all the individual cells in an organism to obtain a cellular broth. The broth is aerated to keep the cells alive while Professor Woo transfers them from the demorphologizer to his patented remorphologizer. This second device re-binds all the cells together to create a new permutation of the organism.

(Those of you who want to try this out at home can replicate Professor Woo's experiment with a large frog, a blender, a packet of gelatin, and a frog-shaped jello mold.)

'Oh', you say, 'I think I can see what's coming now.'

Yes, 'oh'.

Suppose Professor Woo is using one of those really big African bull frogs that's about the size of a human brain, and let's say it has about 10^11 cells in its body and each cell, on average, sits at the center of a 3x3x3 cube of cells. Each cell will therefore have an average of 26 neighbors. This means that there are 2.6x10^12 actual intercellular connections in our big ole frog. But that number is nothing compared to the number of possible permutations, i.e. (2.6x10^12)! That's another one of those awesome bigger-than-the-Universe numbers, eh!

But you see the problem with Professor Woo's logic, don't you?

In that vast space of frog-cell permutations, only a tiny number of arrangements will constitute a viable frog. The rest will just be frog-flavored jello. (Which, by the way, doesn't taste like chicken.) Professor Woo could spend the lifetime of the Universe de- and re-morphologizing frogs without ever seeing a functional frog hop out of the frog mold.

The brain is a hideously complicated network, but it is also highly constrained in the arrangement of neural connections. Even if we only swap a few connections between neurons, instead of blending a whole brain, you could find that your heart only beats when you say the word, 'sausage'. Swap a few different connections and you might find yourself instinctively leaping in front of passing cars. The scope for disaster in randomly rewiring the brain is rather sobering. The portion of 'brain space' that contains properly functioning brains is no more than a tiny, fuzzy point in the space of possible brains. Evolution 'beat' the odds that will flummox Professor Woo's efforts by i) starting really small, and ii) always building on something that already worked. That's the reason we only took 4.5 billion years to emerge from the primordial frog soup.