For over a decade, seed correlation and component analyses have been used to demonstrate correlated brain activity in infants and children ages 1–4 years old. Subjects in these studies were variably sedated, sleeping, or resting, and while the full impact of depth of sleep or sedation on rs-fcMRI correlations is unclear (Horovitz et al., 2009; Larson-Prior et al., 2009), results are broadly congruent across subject cohorts at these ages. Kiviniemi et al. first reported robust correlations of occipital cortex voxels with a primary visual cortex seed in 2000, a finding that has been replicated multiple times in cohorts as young as premature infants less than 30 weeks old (Kiviniemi et al., 2000). Similarly, seeds in auditory (Redcay et al., 2007) and somatomotor cortex (Lin et al., 2008; Smyser et al., 2010) reveal bilateral correlated activity in children as young as 30 weeks gestational age, firmly establishing the presence of correlated rs-fcMRI activity early in development.
