Our interpretation of myelin development trajectories was based on the global mean of the raw myelin content, which increased with age before 36 years (Shafee et al. 2015). Around the age of 36, however, myelin density peaks and then declines with advancing adult age (Grydeland et al. 2013). Extending the interpretation of regional development trajectories of the normalized myelin content to those later age ranges would thus require more complex modeling.
