So here's my two cents:
The brain is a series of links of neurons. (I don't really know much about it's physical anatomy) but here the thing, when you get down far enough, a synapse either triggers or doesn't trigger. At that level, there's no mind to make up. The same structure of a mind should always act the same in the same situation. However, because of reality's ever-changing nature, it is impossible for us to perfectly duplicate any situation. As far as I can tell, a mind is just a series of "If this happens, do this" but with so many variables in it that it is nearly impossible to duplicate.