If creationism is true, one would expect experimental dissection and analysis of the human brain to exhibit near-perfect organization and a lack of additional features to optimize functionality.

1.  Why enable the human brain with the anatomy necessary to doubt its creator?

2.   What evidence do we have that the brain works perfectly? 

3.  Stroke and any kind of severe trauma can severely disrupt the functionality of the brain.  In many ways, the brain is not amenable to repair.  This is why we rely so heavily on stem cell research.  Why would a creator not allow us regenerative capabilities in the brain just like with every other tissue and organ?

4.  We assume that human consciousness is the most advanced and the best because we cannot experience any other form of consciousness...  But we can observe specific differences in conscious experience in other humans.  By this, I mean there would be incredible improvements to humans if certain abnormalities in some humans were distributed all throughout the population.

A)  Synesthesia.  Seeing certain musical notes, numbers, and letters as being associated with color.  This mutation in the human brain allows for essentially quicker learning abilities and a richer conscious experience.

B)  Photographic memory.

C)  Genius -- correlating with specific neuroanatomical differences. 

D)  A severe dysfunction of the brain's emotion system that is not easily subdued.  The limbic system of the human brain is first thought to have arisen in reptiles/amphibians.  The limbic system still has a firm grasp on our consciousness.  In this day and age, it would seem much more intelligent of the creator to create a sort of "mental button" to push when one wanted to change his mood from sad to happy when undesirable levels of unhappiness were experienced.  Instead, we need psychotropic drugs for that.  The limbic system is also responsible for impulse control and aggression.  Why create humans with brains that were so susceptible to control by the limbic system?  In that the structure of the human brain was not altered to prevent limbic system domination of action, God is directly responsible for a gargantuan amount of moral evils committed by humans.

E)  Serial killers, mental illnesses, psychosis.  Why?  Theists will often claim that suffering was allowed into the world because of the fall of adam and eve.  This works for illnesses and diseases that ONLY hurt the person afflicted.  How do you rectify giving a human being a mental disorder that causes him or her to kill others --->  and HOW do you hold such a person accountable for his or her actions if he is found to be neuroanatomically disturbed?