The maturing architecture of the brain's default network.
In recent years, the brain's "default network," a set of regions characterized by decreased neural activity during goal-oriented tasks, has generated a significant amount of interest, as well as controversy. Much of the discussion has focused on the relationship of these regions to a "default mode" of brain function. In early studies, investigators suggested that, the brain's default mode supports "self-referential" or "introspective" mental activity. Subsequently, regions of the default network have been more specifically related to the "internal narrative," the "autobiographical self," "stimulus independent thought," "mentalizing," and most recently "self-projection." However, the extant literature on the function of the default network is limited to adults, i.e., after the system has reached maturity. We hypothesized that further insight into the network's functioning could be achieved by characterizing its development. In the current study, we used resting-state functional connectivity MRI (rs-fcMRI) to characterize the development of the brain's default network. We found that the default regions are only sparsely functionally connected at early school age (7-9 years old); over development, these regions integrate into a cohesive, interconnected network.
Fair
Damien A
DA
Department of Neurology, Washington University, St. Louis, MO 63110, USA. damien.fair@aya.yale.edu
Cohen
Alexander L
AL
Dosenbach
Nico U F
NU
Church
Jessica A
JA
Miezin
Francis M
FM
Barch
Deanna M
DM
Raichle
Marcus E
ME
Petersen
Steven E
SE
Schlaggar
Bradley L
BL
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002648:Child; D006801:Humans; D008279:Magnetic Resonance Imaging; D009415:Nerve Net / Q000502:physiology*