"Psychology and the brain is still firmly in the theoretical. It is not even certain if the soul resides in the brain."
Would the intellect i.e. spirit be the brain of the soul, as the brain is the intellect of the flesh body??? Would it not be the case so long as the brain is functioning to send the signal to breathe the soul still inhabits the body???
The brain appears to be necessary in regulation of some bodily processes. But not all. Some animals and most plants have no brain, and most plants have no nervous system at all, yet they exhibit some behaviors that we associate with the brain, including learning. Plants can have conditioned response and anticipate, slowly, of course. The idea is that the nervous system and the brain accelerate such behavioral responses, but do not originate all of them.