Fig. (4) PET scans from a normal father (A1-A6) and quadruped son (B1-B6). A1, B1: coronal section through occipital cortex and cerebellum; A2, B2: sagittal section through right hemisphere, right cerebellum; A3, B3: transaxial section through putamen; A4, B4: transaxial section through inferior temporal cortex and cerebellum; A5, B5: sagittal section through left hemisphere and left cerebellum; A6, B6: transaxial section through thalamus.