Altered frontal connectivity as a mechanism for executive function deficits in fragile X syndrome.

The controls were matched for age and sex but not for IQ, and adjusting for nonverbal IQ removed some findings, so it is unclear how much reflects fragile X syndrome itself versus general cognitive impairment. EEG was collected at rest while participants watched a silent video, so the findings may not show what happens during real tasks or daily life. Only short-range frontal connections were analysed, so connections outside the frontal lobe that may matter for executive function were not examined. Executive function was measured with a limited computerized battery, and some participants with fragile X syndrome could not complete all subtests because of comprehension difficulties. Many participants were taking psychiatric medication, including stimulants, antipsychotics, and antidepressants. Stimulant use did not affect gamma synchrony but did relate to alpha synchrony differently by sex. Medication effects are hard to separate. The study was cross-sectional and correlational, so it cannot show that altered EEG synchrony causes executive function deficits or that changing synchrony would improve function. Fragile X protein levels were not measured, so the link between protein expression, connectivity, and executive function remains uncertain. Source localization was done without MRI, and the wide age range was not enough to model developmental change across childhood and adulthood.

The only funding statement provided names the National Institute of Child Health and Human Development. No other conflicts are reported in the supplied text.

Do not conclude that frontal EEG synchrony causes executive function deficits or that therapies should target high-frequency or low-frequency brain waves. This was a cross-sectional resting EEG study, not a treatment trial, and some connectivity differences disappeared after accounting for nonverbal IQ.