God, clothed in flowing red robes, is viewed from below and foreshortened, and seems to be rising into the sky. His arms are raised above his head, and he faces up and to his right, exposing his neck and the underside of a short beard. It is here that the study’s authors, the medical illustrator Ian Suk and Dr. Rafael J. Tamargo, a neurosurgeon, believe that Michelangelo concealed a drawing of the underside of the brain and the brain stem, with parts of the temporal lobe, the medulla, the pons and other structures clearly drawn.
God’s beard, usually depicted as long and flowing, appears here short or rolled up to expose the neck. Light provides another hint. The fresco is illuminated from the lower left, but on God’s neck light shines head-on and slightly from the right. The authors insist that Michelangelo, a master of the depiction of light, could only have done this to draw attention to that part of the painting.