White matter fibres overlaid a 3d model of the human brain in top view. Coloured 3D diffusion spectral imaging (DSI) scan of the bundles of white matter nerve fibres in the brain. The fibres transmit nerve signals between brain regions and between the brain and the spinal cord. Diffusion spectrum imaging (DSI) is a variant of magnetic resonance imagine (MRI) in which a magnetic field is maps the water contained in neuron fibers, thus mapping their criss-crossing patterns. Data/software: NIH Human Connectome Project / www.humanconnectomeproject.org).