Objective:Recent studies have found that the brain generates signals in a
wide frequency range. This study aimed to characterize brain activities
from low to high frequency ranges in the developing brain during eyesopen
and eyes-closed. Method: Magnetoencephalography (MEG) data were recorded
from 24 healthy children (6-13 years) and 24 healthy adolescents (14-17
years) during eyes-open and eyes-closed. MEG sources were localized with
accumulated source imaging and analyzed in multi-frequency bands,
including delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30
Hz), low-gamma (30-55 Hz), high-gamma (65-90 Hz), ripple (90-200 Hz),
high-frequency oscillations (HFOs; 200-1,000 Hz), and very high-frequency
oscillations (VHFOs; 1,000-2,000 Hz). Results:Both children and adolescents had
more alpha, less delta, and less low-gamma activity during eyes-closed
compared to eyes-open. Adolescents had less theta, HFOs, and VHFOs,
whereas children had more beta, less high-gamma, and less ripple activity
during eyes-closed compared to eyes-open. During eyes-closed and eyesopen,
adolescents had more theta and VHFO activity, and less low-gamma
and ripple activity, than children. During eyes-closed, adolescents also
had more alpha and less beta than children. Conclusion:Findings suggest that
significant changes in brain activities across a wide frequency range
occurs between eyes-open and eyes-closed, with some differences evident
between children and adolescents. To our knowledge, this is the first
report showing eye closure to modulate source power of HFOs in the
developing brain. Findings indicate that physiological HFOs exist in the
brain and can be detected noninvasively using MEG.