Brain scan. Coloured magnetic resonance imaging (MRI) scan of a coronal (frontal) slice through a head showing a healthy human brain. The cerebrum (centre), which makes up the vast majority of the brain, is split into two hemispheres. It controls conscious thoughts, emotions and movements. Curved over the cerebrum is the skull (white). The nasal sinuses (bottom centre) lie between the eyeballs. MRI scanners produce slice images through the body using a powerful magnetic field and pulses of radio waves. This scan was created at the Laboratory of Neuro Imaging (LONI) at UCLA, USA.