Introduction to Brain Parcellation: From Post-mortem to in Vivo Parcellations

A defining aspect of brain organization is its spatial heterogeneity, which gives rise to multiple topographies at different scales. Brain parcellation — defining distinct partitions in the brain, be they areas or networks that comprise multiple discontinuous but closely interacting regions — is thus fundamental for understanding brain organization and function. After more than one century of histological mapping of brain organization, the past decade has seen an explosion of in vivo MRI-based approaches to identify and parcellate the brain on the basis of a wealth of different features, ranging from local properties of brain tissue to long-range connectivity patterns, in addition to structural and functional markers.
In this course, the main dimensions along which parcellation approaches can be classified will be outlined. Then, as a substantial part of the parcellation literature has been yielded by connectivity-based parcellation, this method will be explained and exemplified. Finally, we will address the current issues, but also future perspectives in the field of brain parcellation.