Brain function relies on a complex interplay of different brain regions. This interplay is known to change during healthy aging, and it can be disrupted in neurological diseases such as dystonia and Parkinson’s disease. In my talk I will present how viewing brain regions as nodes of a graph allows us to employ methods from the mathematical field of graph theory to better understand brain function. I will highlight that by investigating communication across the whole-brain network, it is possible to gain insight into how the brain functions, how neurological conditions and age affect the brain, and how the brain can ensure function through compensatory mechanisms in network communication.