Reliability of resting-state electrophysiology in fragile X syndrome

Validating brain activity measures as reliable indicators of individual diagnostic group and genetically mediated sub-group membership Fragile X Syndrome

“…Resting power abnormalities in FXS may re ect similar mechanisms for gamma power enhancement [16,30] or may re ect thalamic or hippocampal inhibitory de cits via changes to cross-frequency coupling between theta, alpha and gamma power [9,12,31]. Reliability across multiple testing remains an open question, although preliminary work suggests moderate to strong reliability for resting EEG in a wide range of individuals with FXS [32] and moderate reliability for gamma power during auditory tasks, at least in young individuals with FXS [33]. In this study, we utilized guided machine learning to delineate individual level predictions for diagnostic group and subgroup membership (FXS or CON, sex and mosaicism status), to address the third requirement for an effective biomarker.…”

“…However, the cross-validation error was generally robust for the non-mosaic male sub-group on best performing variables, somewhat mitigating this concern. Secondly, ideally in a biomarker validation study retest reliability would also be considered, however retest data was not available for all individuals (but see [32]) and is thus an ongoing pursuit for future study. Third, we only analyzed classi cation accuracy within task, and did not evaluate combined accuracy across rest and chirp tasks.…”