Thanks for the clarification. Now it's clearer why you wrote the first comment.

1. I think you and I have different understanding of that myth. I was referring to the fact that people think 90% is not used at all. I might have done a poor job of emphasizing that thing, that's why we are discussing this now.

2. I haven't looked at it that way. It's an instance when the paragraph name interfered with some important concepts in the entire article... The point in "Size Does Not Matter" that I have envisioned is that being a such a small fraction of the body, the brain consumes unproportionately more energy.

The point of Ritalin and Cola is that those increase the blood glucose level, which aids in cognitive processes.