Myelin is a fatty substance that supports healthy brain function by strengthening communication between different brain areas. Myelin also plays in important role in reducing neural plasticity,
stabilizing the development of neural circuits that support complex behavior. We used non-invasive MRI indices of cortical myelin content from the Human Connectome Project-Development (HCP-D) to characterize the rate and timing of myelin development from childhood through early adulthood. HCP-D is a large NIH-funded research initiative comprising approximately ∼1750 open access datasets from 1300+ healthy human participants, ages 5-21 years, including cognitive, emotional, and multimodal neuroimaging data acquired at four demographically diverse sites across the USA. Our study used structural neuroimaging data from a subset of the HCP-D, including 628 individuals between the ages of 8 and 21.