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Compare Brains

Compare Brain and Body Sizes

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The Neuron- Up Close and Personal

The Question of Intelligence
  1. absolute size
  2. brain/body size
  3. cortical folding
  4. neocortex
  5. gray matter/nerve cells
  6. specific brain structures




What were some of the characteristics of the brains that we saw?

One thing we noticed is that each of the brains have slightly different degrees of folding in the cerebral cortex . Is that significant? Yes!

If we look at evolutionary patterns, we will see that the brain areas that show the most changes are the cerebral hemispheres and cortex (the outer-most layer of the cerebral hemispheres). The more recently evolved animals tend to have more cerebral cortex than less "evolved" animals. In some animals, especially "higher" mammals, the surface of the cerebral cortex is folded, creating grooves ("sulci") and bumps ("gyri") on the surface of the brain (which is what we observed earlier). This folding increases the surface area of the cortex.

Any guesses as to why this is important?? Well, the first step is to guess what the cerebral cortex does . . . Think about it . . .
. . . As animals evolved from a simpler organisms to complex beings such as dolphins, monkeys, and humans, the cerebral cortex changed and evolved as well. What kinds of behavioral characteristics distinguish humans from, say, a mouse? (no- we're not talking about comparative cheese-cravings!!)

brain sizes image
(image thanks to soton.ac.uk/~jrc3/chudler/brainsize.html)

So, what exactly does the cortex do?

Huh? Can we start over?