The individual alpha bandwidth: A trait-like neural marker associated with sensory processing and executive function.

Area of Science:

• Neuroscience
• Cognitive Science
• Psychology

Background:

• Alpha oscillations are key brain rhythms, with peak frequency (IAF) extensively studied.
• The width of the alpha band (individual alpha bandwidth, IAB) remains under-explored.
• IAB may offer complementary insights into brain function and individual differences.

Purpose of the Study:

• To investigate the reliability and functional relevance of individual alpha bandwidth (IAB).
• To compare IAB estimation methods and their association with sensory and cognitive processes.
• To explore methodological and experimental factors influencing IAB's functional relevance.

Main Methods:

• Analyzed four electroencephalography (EEG) datasets using a unified preprocessing pipeline.
• Assessed test-retest reliability of IAB.
• Compared IAB estimation using Savitzky-Golay filter (SGF), FOOOF, and amplitude-difference methods; examined associations with perceptual (P2 amplitude) and cognitive (flanker interference, N450) measures.

Main Results:

• IAB demonstrated good-to-excellent test-retest reliability, indicating trait-like stability.
• IAB estimated via SGF, but not FOOOF or amplitude-difference, correlated with sensory and cognitive functions.
• Wider IAB associated with enhanced perceptual processing (larger P2) and cognitive control (smaller flanker effect, larger N450), dependent on state (eyes-closed/open rest) and frequency window.

Conclusions:

• Individual alpha bandwidth (IAB) is a reliable neural marker for individual differences in sensory and executive functions.
• The functional relevance of IAB is method-dependent (SGF effective), state-dependent, and frequency-window dependent.
• IAB offers valuable insights beyond peak alpha frequency, but careful methodological consideration is crucial for future research.