Defining and describing the functional network organization of the healthy human brain, with observations on development and disease

Abstract

This thesis concerns the general functional organization of the healthy human brain. In contrast to studies of organization based on lesions or task-evoked activity, brain organization is studied using task-free measures of association between brain regions, namely resting state functional connectivity fMRI (RSFC). This technique measures relationships between brain regions using correlations in spontaneous, low-frequency BOLD signal, and is described in Chapter 1. In Chapter 2, we outline the general RSFC network structure of the healthy adult brain. In Chapter 3, we examine brain network structure for evidence of critical nodes in the system. In Chapter 4, as part of a collaboration, we test and confirm these predictions in a large neuropsychological database. Chapter 5 describes a novel motion-related artifact in resting state fMRI. Chapter 6 describes methods to eliminate artifactual influences of motion on cohort comparisons. Chapter 7 describes ongoing and future efforts building on the data presented in Chapters 2-6.