Why does the brain need to have a larger surface and not a larger volume?



I was reading the Selfish Gene and I got to the part where the autor says that the human brain stores data much more efficiently and has a much more complex retrieval mechanism of memories than a computer counterpart. If storage and access are the goals, wouldn’t a “smooth” brain make more sense?

In: Biology

Only the surface of the brain (oversimplifying but generally correct) has the cell bodies where ‘meat’ of the brain actually is. It does all the processing and thinking. The rest of the brain is just wires that connect the bits of the surface together. Having a really folded brain means that these connections don’t have to be as long.

Its a logistical problem.

What limits the brain is not how much brain cells you can pack into your head, but how you can feed all those cells.

The brain cells get nutrients from blood, but blood cant flow freely into the brain – its absorbed via the surface of the brain. Thus, the larger the surface, the more nutrients can be absorbed, and the more braincells you can have.

If your brain was a smooth ball, the cells further inside would simply starve (and die from their own excretions, which wouldnt be properly removed).

A brain stores information through the reinforcing of relationships between neurones. What’s important in this is the points those neurones interact, but that’s not what all of the brain is. For some unknown reason, grey matter – the part of the brain where the interactions happen – is only found on the surface of the cortex, while the insides are just the long thin bits (axons) of neurones relaying information to and from the grey matter. So, since the processing bit only occurs at the surface, the more surface you have, the more processing you can have, and the only interior space you’re losing when you fold like this is white matter space, which isn’t a problem cos you can just make the axons shorter.