3-D brain scan. Coloured three-dimensional magnetic resonance imaging (MRI) scan of the healthy brain of a child seen from above. The front of the brain is at top. The cerebrum, which makes up the vast majority of the brain, is split into two hemispheres whose outfolded gyri are fissured with sulci. It controls conscious thoughts, emotions and movements. MRI scanners produce slice images of the body using a powerful magnetic field and pulses of radio waves. Successive slices can be compiled into a three- dimensional image by a computer. This scan was produced at the Laboratory of Neuro Imaging (LONI) at UCLA, USA.