Alpha oscillations are dysrhythmic in Fragile X syndrome

Area of Science:

• Neuroscience
• Computational Neuroscience
• Genetics

Background:

• Alpha oscillations are key brain rhythms for neural coordination and inhibitory control.
• Dysfunctional alpha dynamics are linked to neuropsychiatric and neurodevelopmental disorders.
• Fragile X syndrome (FXS) presents paradoxical alpha power (elevated absolute, reduced relative), requiring deeper analysis beyond simple power metrics.

Purpose of the Study:

• To investigate alpha oscillation temporal dynamics in FXS using cycle-by-cycle burst analysis.
• To decompose nonspecific alpha abnormalities in FXS into specific temporal features.
• To model alpha burst features and identify group, sex, and regional differences.

Main Methods:

• Utilized cycle-by-cycle (bycycle) alpha burst analysis on resting-state EEG data.
• Analyzed data from 70 individuals with FXS and 71 typically developing controls.
• Employed statistical modeling (generalized linear mixed-effects models) to examine burst features.

Main Results:

• FXS males showed reduced alpha burst count; both sexes exhibited prolonged burst durations and elevated amplitudes (especially males).
• Timing dysregulation was found in cognitive-control regions, while amplitude elevations occurred in sensory cortices.
• Alpha burst amplitude correlated with hyperactivity and inversely with intelligence in FXS; burst count correlated with age.

Conclusions:

• Resolved paradoxical alpha power in FXS by identifying specific temporal burst features.
• Findings suggest interneuron dysfunction as a potential mechanism in FXS.
• Demonstrated the utility of burst-level analysis for hypothesis generation and biomarker development in neurodevelopmental disorders.