I am inclined to believe this is rather implausible, but I am not above acknowledging the possibility of future developments which might make such measurements feasible, subsequently pointing to a separate mind and brain. Second, our current methods of measurement and inference may not be entirely valid. Perhaps a fMRI is telling us that flashes of light are not only stimulating the occipital lobes, but causing messages to be relayed to a mind which is separate from the brain which is not being concurrently measured or observed by the researcher. All we see is activity in particular brain regions, and we make the inference that the activity represents responsibility for function. It is possible, though currently unfalsifiable, that the activity is representative of interplay between mind and brain rather than the sole work of the brain.
Most religions depend on the passage of the soul from the earthly level to some other.
For example, a Christian cannot go to heaven or hell if the mind, brain, and soul are the same and, thus, die with the body. Considering the vast number of people for whom faith in a soul-centered religion is an essential part of their lives, the impact of this issue is very significant. Granted, this does not provide any evidence that the mind and brain are not synonymous, but I cannot prove that soul-centered religions are false. These religions are also conveniently unfalsifiable, but if they are true, then it seems to follow that the mind and brain are separate. The reasons for the mind and brain's union seem much more ostensible than the ideas to the contrary.