Connectivity

The connectivity of neuronal systems is their most fundamental characteristic. Here, we focus on recent developments in understanding structural and functional connectivity at the macroscale, which is accessible with current imaging technology. Structural connectivity is examined via diffusion weighted imaging methods, of which diffusion tensor imaging is the most frequently used. Many cross-sectional and an increasing number of longitudinal studies using diffusion tensor imaging have been recently conducted over the period of development starting with newborns. Functional connectivity has been studied through task-based functional magnetic resonance imaging, and increasingly through studies on task-free functional imaging, also known as resting state functional imaging. The study of intrinsic functional connectivity beginning during fetal life reveals the developmental organization of intrinsic connectivity networks such as the default mode network, the dorsal attention network, the frontal-parietal executive control network, as well as primary cortical networks. As methods of examining both structural and functional connectivity mature, they increasingly inform our understanding of the development of connectivity in service of the long-term goal of delineating the substrates of much of developmental psychopathology.