Aperiodic and Hurst EEG exponents across early human brain development: A systematic review

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Computational Neuroscience

Background:

• Electroencephalographic (EEG) power-frequency slope exponents (1/f^β) serve as non-invasive biomarkers for neural activity's excitation-inhibition (E:I) balance.
• Altered E:I balance is implicated in neurodevelopmental conditions, making the developmental trajectory of 1/f^β crucial for early detection and intervention.
• Understanding the maturation of these EEG measures during early development (0-26 years) is essential for characterizing typical brain development.

Approach:

• A systematic review (PROSPERO-ID: CRD42023363294) was conducted to explore the early maturation of resting-state EEG 1/f measures.
• Studies included those with at least one 1/f measure and a minimum of 10 typically developing participants.
• Data from 42 studies (N=3478) were narratively synthesized, with risk of bias assessed using the Quality Assessment with Diverse Studies tool.

Key Points:

• Narrative synthesis of Hurst Exponent (HE) data indicates non-stationary EEG activity persists throughout development.
• Age-related trends in aperiodic exponents (AE) revealed rapid decreases during infancy, followed by heterogeneous changes.
• Developmental shifts in AE maxima suggest evolving spatial patterns in maturing brain connectivity.

Conclusions:

• The development of EEG 1/f measures is complex and varies across infancy and childhood.
• These findings underscore the need for further characterization of 1/f measure development.
• A deeper understanding of 1/f measure maturation is vital for elucidating how E:I balance influences brain and cognitive development.