First, I never said that 'mind' was immaterial, which is one of the major differences between my point of view and standard Dualism. I think we covered this topic in some depth in our discussion of God as organized energy, which is no different than what I view 'mind' or soul to be. Energy is very physical, and thus there is no interaction problem between an energy form and the brain, which is by design quite adept at manipulating and responding to energetic influences.