Brain Designer...
I was looking at this from the literal perspective, I divided it into smaller units by looking at brain and designer separately. The brain meaning the human brain and the designer as a normal designer, someone who designs something.
Adding both of them together, we can say it is a person that designs the brain. Maybe he is a builder of brain, this will go into anatomy and the use of brain work.
A designer is more emotional and is better in tune with their own feelings and therefore is able to express those feelings in a greater capacity.Link
Some interchange the brain designer as the head designer meaning the head of an organisation because he serves as the head or the brain of the organisation, which can be said as the brain designer.
I think the latter is more reasonable than the former because humans do not create or design the brain.
Thank you for your time...