Intrasubject variability of sustained attention is associated with elevated self-reported attention deficits in women with a fragile X premutation allele.

Women with a fragile X premutation (PM) self-report higher rates of attention difficulties than women without a PM; however, results of studies using objective measures of attention are inconsistent. The present study assessed whether intrasubject variability during a sustained attention task better predicted functional outcomes in women with a PM than the previously published standard reaction time and accuracy variables.