Evidence on the emergence of the brain's default network from 2-week-old to 2-year-old healthy pediatric subjects

Wei Gao, Hongtu Zhu, Kelly S. Giovanello, J. Keith Smith, Dinggang Shen, John H. Gilmore, Weili Lin

Research output: Contribution to journalArticlepeer-review

397 Citations (Scopus)


Several lines of evidence have implicated the existence of the brain's default network during passive or undirected mental states. Nevertheless, results on the emergence of the default network in very young pediatric subjects are lacking. Using resting functional magnetic resonance imaging in healthy pediatric subjects between 2 weeks and 2 years of age, we describe the temporal evolution of the default network in a critical, previously unstudied, period of early human brain development. Our results demonstrate that a primitive and incomplete default network is present in 2-week-olds, followed by a marked increase in the number of brain regions exhibiting connectivity, and the percent of connection at 1 year of age. By 2 years of age, the default network becomes similar to that observed in adults, including medial prefrontal cortex (MPFC), posterior cingulate cortex/retrosplenial (PCC/Rsp), inferior parietal lobule, lateral temporal cortex, and hippocampus regions. While the anatomical representations of the default network highly depend on age, the PCC/Rsp is consistently observed at in both age groups and is central to the most and strongest connections of the default network, suggesting that PCC/Rsp may serve as the main "hub" of the default network as this region does in adults. In addition, although not as remarkable as the PCC/Rsp, the MPFC also emerges as a potential secondary hub starting from 1 year of age. These findings reveal the temporal development of the default network in the critical period of early brain development and offer new insights into the emergence of brain default network.

Original languageEnglish
Pages (from-to)6790-6795
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number16
Publication statusPublished - 2009 Apr 21


  • Brain development
  • Resting functional magnetic resonance imaging

ASJC Scopus subject areas

  • General


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