Rose, S. A., Wass, S., Jankowski, J. J., Feldman, J. F., & Djukic, A. 2017. Neuropsychology
Objective. The object of the present study is to advance our understanding of the cognitive
profile of Rett Syndrome (RTT), an x-linked neurodevelopmental disorder caused by mutations
in the MECP2 gene. We focus on sustained attention, which plays a critical role in driving
cognitive growth, and use an innovative, gaze-based task that minimizes demands on the limited
verbal and motor abilities associated with RTT.
Method. The task required the ability to sustain attention on a visual target (a butterfly) whilst
inhibiting a prepotent response to look to moving distractors (trees and clouds) presented in the
peripheral visual field. The sample included children with RTT (N = 32) and their typically
developing (TD) counterparts (N = 32), aged 2-12 years.
Results. Our findings revealed that children with RTT had more difficulty sustaining attention
(with the TD group averaging 60% looking at the butterfly vs only 25% for the RTT group).
Furthermore, they showed that RTT was associated with difficulties in three fundamental factors
influencing sustained attention: engagement, distractibility, and re-engagement. The RTT group
was slower to engage, more distractible, and slower to re-engage.
Conclusion. Our findings suggest there may be a fundamental disruption to sustained attention
in RTT, identifies factors related to this impairment, and points to cognitive areas that could be
assessed in evaluating the usefulness of interventions.