In adopting an erect attitude, humanity has distorted its rostral-caudal axis as shown in the bent red double-headed arrow. The brain accordingly has anatomical axes out of line with non-bipedal mammals, and, as shown in the yellow arrows, at odds with the Standard Anatomical Position . The directions of the arrows are annotated as follows: Red axis showing how the head bent forward as the back pointed upwards: c: Caudal r: Rostral The Yellow axes show the conventions for naming the directions in the brain itself: c: Caudal (although it is not the tail direction), d: Dorsal r: Rostral (effectively unchanged) v: Ventral (although it is not the belly direction)