Healthy brain. Computer-enhanced Magnetic Reson- ance Imaging (MRI) scan of a human brain, in side view. This is a sagittal slice" through the brain in profile. The face is at left with the nasal and mouth cavities coloured orange. The brain is green/yellow, with cranial spaces pink. At top, the cerebrum of the brain appears folded (green); this is the region where intelligent thought processes and memory occur. At centre (yellow) is the elongated brainstem which controls involuntary reflexes; it connects with the spinal cord. An MRI scan is obtained using a powerful magnet and radio waves. It enables structures in the brain to be seen, including brain tumours."