1 research outputs found
Hemispheric Utilization of Alpha Oscillatory Dynamics as a Unique Biomarker of Neural Compensation in Females with Fragile X Syndrome
Fragile X syndrome (FXS) is a neurodevelopmental
disorder caused
by a trinucleotide expansion on the FMR1 gene and characterized by
intellectual disability, sensory hypersensitivity, executive function
difficulties, and social anxiety. Recently, efforts to define neural
biomarkers for FXS have highlighted disruptions to power in the alpha
frequency band; however the dynamic mechanisms supporting these findings
are poorly understood. The current study aimed to explore the temporal
and hemispheric dynamics supporting alpha phenotypes in FXS and their
relationship with neural phenotypes related to auditory processing
using electroencephalography during an auditory evoked task. Adolescents
and adults (N = 36) with FXS and age/sex matched
typically developing controls (N = 40) completed
an auditory chirp task. Frontal alpha power in the prestimulus period
was decomposed into “bursts” using percentile thresholding,
then assessed for number of bursts per second (burst count) and burst
length. Data were compared across left and right hemispheres to assess
lateralization of neural activity. Individuals with FXS showed more
differences in alpha power compared to TDC primarily in the right
hemisphere. Notably, alpha hemisphere outcomes in males with FXS were
driven by the number of times they entered a dynamically relevant
period of alpha (burst count) rather than length of time spent in
alpha. Females with FXS showed reduced burst counts but remained in
sustained high alpha states for longer periods of time. Length of
time spent in alpha may reflect a modulatory or compensatory mechanism
capable of recovering sensory processing abilities in females with
FXS resulting in a less severe clinical presentation. Right hemisphere
abnormalities may impact sensory processing differences between males
and females with FXS. The relationship between alpha burst length,
count, sex, and hemisphere may shed light on underlying mechanisms
for previously observed alpha power abnormalities in FXS and their
variation by sex