A couple of the books some of us read in the 00s had to do with the brain and the soul. A Monday lunch reading group read Joel Green's Body, Soul, and Life. And at another time we read How God Changes Your Brain. Some basic points, neither of them particularly new or shocking, seemed clear from those discussions.
The first is that who we are--even spiritually--has an awful lot to do with our brains. As simple as this sounds, I suspect the word on the street doesn't quite get it. You look at a host of movies and popular church banter and there is this sense that most of who we are is in our spirit or detachable soul. When I taught philosophy, students seemed very attracted to the idea that an Alzheimer's patient was really in there somewhere but the brain was making it difficult for them to get through.
I suspect that one's sense of such things changes drastically when one knows even a little about the brain. It does not disprove anything about the Holy Spirit to recognize that a doctor could induce a religious experience by applying a little electricity to a certain part of your brain. Alter my brain's physical structure and you alter my memories, my personality, and my spirituality.
A second realization is of course that it is difficult to know whether our Christian language of the soul is metaphorical or literal. I'm not sure how we could decide, frankly, even as Christians. The idea of a detachable soul is very convenient, mind you, and this is certainly the way Christians have talked for centuries. Some parts of the Bible talk this way as well--although not as consistently as you might think.
For example, the Old Testament in no instance speaks of the soul as a detachable part of a human that contains our personality, memories, etc. It does not talk of the human spirit in this way either. In the New Testament, only a small part uses this language of a part of me that might survive death. The focus is on bodily resurrection in the afterlife, not some disembodied afterlife. N. T. Wright has of course emphasized this as well (maybe too much, even).
So is our language of the soul metaphorical or literal? This is a question I don't think we can be dogmatic about if we actually know the issues. It was fun to be part of a group at IWU that was discussing these issues right along with everyone else when it was the big topic in the 00s.