A comparison of resting-state eyes-closed and dark-room alpha-band activity in children

Area of Science:

• Neuroscience
• Developmental Psychology
• Biomedical Engineering

Background:

• Resting-state (RS) alpha oscillations (8-12 Hz) are dominant in relaxed, eyes-closed states, particularly in parietal-occipital regions.
• RS alpha is linked to information processing speed and network information processing.
• Traditional RS eyes-closed (EC) protocols exclude populations like infants, toddlers, and individuals with intellectual disabilities.

Purpose of the Study:

• To evaluate the viability of a dark room, eyes-open (DR) resting-state alpha measurement as an alternative to the traditional eyes-closed (EC) protocol.
• To compare the reliability and characteristics of RS alpha measures obtained via DR and EC methods.
• To assess these methods in children with typical development (TD) and autism spectrum disorder (ASD).

Main Methods:

• Magnetoencephalography (MEG) was used to record resting-state alpha activity.
• Participants included children with TD (N=37) and ASD (N=30), aged 6.9-12.6 years.
• Alpha activity was measured under both traditional eyes-closed (EC) and dark room, eyes-open (DR) conditions.

Main Results:

• Both RS EC and DR peak alpha frequency demonstrated good reliability (ICC = 0.83).
• Posterior alpha power was slightly reduced (~5%) in the DR condition compared to EC, with slightly lower reliability (ICCs in the 0.70s).
• No significant differences in EC versus DR associations were found between TD and ASD groups; age correlated with both measures.

Conclusions:

• The dark room, eyes-open resting-state alpha exam is a viable alternative to the traditional eyes-closed method.
• This DR approach enhances the inclusivity of electrophysiology resting-state studies for diverse populations.
• Findings support the use of DR alpha measures for research in pediatric populations, including those with ASD.