Not a ton of info here but thought I'd pass it along if anyone is interested:

"Studies of lucid dreamers visualize which centers of the brain become active when we become aware of ourselves."
http://www.eurekalert.org/pub_releases/2012-07/m-tso072712.php

It appears you need to be a subscriber to the journal "Sleep" to view the entire article but some of you may have access via a University library nearby if you're interested in the whole article.

Metta,

Brian.

In some of the few times I got lucid in a dream, I did feel some parts of the brain becoming more activated. It was like a quick change of pressure in a lateral area of the skull(both sides).
This change is quite noticeable to me, even though I didn't feel it every time, so I don't know why people never comment on it.
Once even I started to suspect it was a dream, I was still normal, but when I got "evidence" it was a dream, I could feel this difference.