Abstract
Functional activity in the human brain is intrinsically organized into independently active, connected brain regions. These networks include sensorimotor systems, as well as higher-order cognitive networks such as the default mode network (DMN), which dominates activity when the brain is at rest, and the frontoparietal (FPN) and salience (SN) networks, which are often engaged during demanding tasks. Evidence from functional magnetic resonance imaging (fMRI) suggests that although sensory systems are mature by the end of childhood, the integrity of the FPN and SN develops throughout adolescence. There has been little work to corroborate these findings with electrophysiology. Using magnetoencephalography (MEG) recordings of 48 participants (aged 9–25 yr) at rest, we find that beta-band functional connectivity within the FPN, SN, and DMN continues to increase through adolescence, whereas connectivity in the visual system is mature by late childhood. In contrast to fMRI results, but replicating the MEG findings of Schäfer et al. (Schäfer CB, Morgan BR, Ye AX, Taylor MJ, Doesburg SM. Hum Brain Mapp 35: 5249–5261, 2014), we also see that connectivity between networks increases rather than decreases with age. This suggests that the development of coordinated beta-band oscillations within and between higher-order cognitive networks through adolescence might contribute to the developing abilities of adolescents to focus their attention and coordinate diverse aspects of mental activity.NEW & NOTEWORTHY Using magnetoencephalography to assess beta frequency oscillations, we show that functional connectivity within higher-order cognitive networks increases from childhood, reaching adult values by age 20 yr. In contrast, connectivity within a primary sensory (visual) network reaches adult values by age 14 yr. In contrast to functional MRI findings, connectivity between cognitive networks matures at a rate similar to within-network connectivity, suggesting that coordination of beta oscillations both within and between networks is associated with maturation of cognitive skills.
Highlights
Fox et al (2005) showed that a network of “task-positive” brain regions that show increased blood oxygenation level-dependent (BOLD) signal in response to cognitively demanding tasks is anticorrelated at rest with a network of “task-negative” regions that show decreased BOLD signal, a network known as the default mode network (DMN)
We found that positive correlations between beta amplitude envelopes increased between nodes of the DMN, frontoparietal network (FPN), and salience network (SN) throughout adolescence and into young adulthood
The increase in correlation strength between the three attentional networks (DMN, FPN, and SN) followed a trajectory similar to that of the correlations within these networks. In contrast to these slowly maturing correlations within and between attentional networks, we found that correlations between nodes of the visual network (VN) matured rapidly during childhood
Summary
Fluctuations in fMRI blood oxygenation level-dependent (BOLD) signal over time, assumed to reflect neural activity, are correlated between brain regions. These correlated regions form the nodes of multiple distinct networks that exhibit consistency in spatial configuration across individuals. If the effect of global fluctuations is not removed, the correlations between DMN and task-positive sites are typically near zero (Fox et al 2009), whereas within-network correlations are positive.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
