Fifteen Carmelite nuns came from the monastery to the laboratory to enter a huge fMRI machine whilst meditating, allowing scientists there to scan their brains using fMRI while they were in a state known as Unio Mystica (and also Theoria). The results showed that far-flung parts of the brain were recruited in the sustaining of this mystical union with God.

http://en.wikipedia.org/wiki/Research_on_meditation