SPECT scans were taken of subjects while worshiping (left) versus "speaking in tongues" (right). The images from subjects "speaking in tongues" primarily show a decrease of brain activity in the frontal lobes, which is what normally makes us feel as if we’re in control. There was also a decrease in activity in the left basal ganglia, which is involved with focusing attention and emotional responses. Finally, the thalamus activity increased during speaking in tongues which supports it is an active state of the brain.

Image Credit: University of Pennsylvania School of Medicine