Date of Award

Summer 8-15-2019

Author's School

Graduate School of Arts and Sciences

Author's Department

Biology & Biomedical Sciences (Neurosciences)

Degree Name

Doctor of Philosophy (PhD)

Degree Type



The human brain is organized at many spatial scales, including the level of areas and systems. Resting-state functional magnetic resonance imaging is a non-invasive technique that allows for the study of areal- and systems-level brain organization in vivo. Over two decades of research has sought to identify and characterize the functional communities that comprise the brain’s network architecture. Consequently, a convergent description of group-average functional network organization in healthy adults has emerged. Recent advances have allowed for the study of such organization in single individuals. Investigation of functional network organization in highly sampled individuals has revealed brain regions that deviate from the group-level description, i.e. individual differences in human brain functional network organization. This dissertation work characterizes individual differences in functional network organization, referred to as network variants, across a large sample of healthy adults. Network variants appear to be stable over time within an individual and organized systematically across individuals. They occur in characteristic cortical locations and associate with characteristic functional networks. Further, their task-evoked activity is consistent with their idiosyncratic functional network association. Finally, individuals may be sub-typed into one of two groups, where individuals in the same sub-group have a similar distribution of network variants. The sub-group phenomenon is heritable and relates to differences in neuropsychological measures of behavior. Network variants appear to be trait-like, functionally-relevant components of individual human brain functional network organization.


English (en)

Chair and Committee

Steven E. Petersen

Committee Members

Deanna M. Barch, Christina N. Lessov-Schlaggar, Bradley L. Schlaggar, Joshua S. Shimony,


Permanent URL: https://doi.org/10.7936/09xf-9f06