There has been a concerted effort to delve into the psychological and biological aspects of the subject under the umbrella of NARTH (http://www.narth.com). Looking at brain only, at best tells us half the picture. The other half will not show up on biopsy or X-ray, it is called soul. And theology that I consider reliable posits that the soul has become polluted at some point logically if not temporally prior to incarnation. We know it as the fall of man and it played out in the Garden of Eden at the Serpent's cunning call, but it involved everybody in a manner the bible declines to spell out the exact details of.
Anyhow, one of the interesting observations of NARTH, IIRC, is that the brain can change with the way it is used. If we refuse to be shackled down by materialism, then we can readily affirm that this has to do with soul. And because there is also now a Savior in the world, soul can choose redemptive goodness now, not mere Edenic goodness.
Well said. Hard for some to quantify the soul.
It causes the hair to raise and tears to form when I contemplate. It is still me after the physical part has departed or died.