This whole separation of mind and physical brain is so intuitive yet so foreign to me. What happens at the boundary (interface) between the two? Is such a question approachable/tractable by science and scientific methods?
As a pragmatic consideration, I do not see any real reason for considering the two separately. Here we are, these biological beings that live, reproduce, and die. Why must there be a physical or metaphysical soul? What within the framework of our understanding of God must allow for a physical soul to emerge? How is the mind different from the brain? What are the markers of a mind that are non-biological?
There is good evidence to suggest that neural activity can be traced in vivo on a sub-cellular level for every cognitive process through which we go (conscious or subconscious), including any spiritually based activity. Do physical changes occur? If there is any feeling or semblance that one’s perception of the world has changed after such an experience, then the idea is that the plasticity of the brain will be manifested in some type of neural change.
How does one define the mind? By what criteria can the idea of consciousness be expressed? Perhaps it is an unoriginal idea, but the best definition I have ever heard for consciousness is something to the tune of “appreciation of art.” I am not personally familiar with any well controlled experiments on the subject concerning lower mammals and the expression of an appreciation for art, but I do believe that it is not the creation of art but possibly the enjoyment of art that sets us apart biologically. If this can serve as a biological definition – albeit an untied, poorly thought out one – then it would predict that, if the hypothesis is that humans are the only conscious beings, then other animals would not show an appreciation or enjoyment of art.
How would this be measured? Well, I don’t know of many monkeys that are willing to discuss the annals of music, poetry, and sculpture, but certainly these things are just output from a system that has other biological markers of activity in pleasure-reward areas and “emotional discharge,” which is merely localized chemical activity possibly coupled with detectable rhythms and certain footprints of neural activity. If a framework can be developed that can show preference or appreciation from a biological basis, only then can one proceed to test in animals with which one cannot otherwise communicate.
A further prediction is then that even people who don’t necessarily like art will have similar neural responses that correspond to what is often called a “subconscious” appreciation thereof.
You see, such ramblings aside, science cannot even begin to approach the problem of consciousness for the same two reasons we have not found a grand unified theory of physics: (1) the definition/theory must be consistent with our present understanding and (2) the theory must make testable predictions that can be independently and experimentally verified. This is the very essence of the scientific method.