Brain imaging genetics looks at how differences in genes (the part of our DNA that makes us who we are) affect our brains. The connections between different parts of the brain, and the way the brain develops are all influenced by genes. Usually, when scientists look for genetic effects in the brain, they look for really broad characteristics such as the the sizes, or thicknesses of the different parts of the brain. This is useful for giving us a big picture about what’s happening, but it hasn’t led to any deep understanding of genetic neurodegenerative diseases (instead, it provides more of a description rather than an understanding). The main tool for measuring the brain in humans is magnetic resonance imaging (MRI). The MRI produces a three dimensional picture of the brain. The “pixels” of the picture are known as voxels (as they are volumetric). There are many voxels in each MRI picture, and the complexity and size of the picture is the reason scientists have so far only looked at broad effects. By using modern machine learning and statistical techniques, the challenge of looking for genetic effects at the level of the voxel can be overcome.