Elevated gamma spectral event peak power during auditory chirp is associated with neuropsychiatric features in Fragile X syndrome.

OBJECTIVE

Investigate transient, non-averaged electroencephalography (EEG) signals in the gamma frequency band during an auditory chirp paradigm in individuals with Fragile X syndrome (FXS), a population characterized by elevated background gamma power, and to assess their relationship with clinical features.

METHODS

Source-localized EEG responses to auditory chirp stimulus were studied in 36 individuals with FXS and 39 typically developing controls (TDC). Transient high-power gamma-band events were extracted using a thresholding approach. Gamma event properties were compared between groups and correlated with mean EEG features and clinical measures.

RESULTS

In male FXS subjects, gamma event peak power was increased in the temporal source and lacked correlation with inter-trial coherence (ITC). Event rate, duration, and frequency span were similar between groups. Event peak power was positively correlated with obsessive and stereotyped behavior scales.

CONCLUSIONS

Peak power of transient gamma events during auditory response is tonically elevated, dissociated from phase synchronization, and associated with neuropsychiatric features in FXS.

SIGNIFICANCE: Identifying a tonic elevation of gamma event peak power in FXS during auditory processing suggests altered neural circuit mechanisms underlying aberrant gamma activity. This provides a more direct basis for understanding auditory hypersensitivity, fostering opportunities for back translation and targeted treatment development.