This study investigates the use of functional magnetic resonance imaging (fMRI) to identify a neuromarker of sustained attention, an important aspect of cognitive function. The researchers developed a model called the Sustained Attention Network (SAN) based on whole-brain functional connectivity during a sustained attention task. The SAN model predicted individual differences in task performance and, surprisingly, predicted clinical measures of attention deficit hyperactivity disorder (ADHD) symptoms in a separate sample of children and adolescents. The study demonstrates that whole-brain functional network strength is a robust and broadly applicable neuromarker of sustained attention, providing a valuable tool for researchers and clinicians to assess and track attentional abilities. The findings also highlight the importance of considering the broader network architecture rather than individual regions when studying attentional processes.This study investigates the use of functional magnetic resonance imaging (fMRI) to identify a neuromarker of sustained attention, an important aspect of cognitive function. The researchers developed a model called the Sustained Attention Network (SAN) based on whole-brain functional connectivity during a sustained attention task. The SAN model predicted individual differences in task performance and, surprisingly, predicted clinical measures of attention deficit hyperactivity disorder (ADHD) symptoms in a separate sample of children and adolescents. The study demonstrates that whole-brain functional network strength is a robust and broadly applicable neuromarker of sustained attention, providing a valuable tool for researchers and clinicians to assess and track attentional abilities. The findings also highlight the importance of considering the broader network architecture rather than individual regions when studying attentional processes.