Computer artwork of a MRI top view of the brain showing white matter fibres. 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 imaging (MRI) in which a magnetic field maps the water contained in neuron fibres, thus mapping their criss-crossing patterns. A similar technique called diffusion tensor imaging (DTI) is also used to explore neural data of white matter fibres in the brain. Both methods allow mapping of their orientations and the connections between brain regions. Data software: NIH Human Connectome Project www.humanconnectomeproject.org).