Given that a sizeable proportion of the PTPN11 (20%) and SOS1 (50%) groups were taking stimulant medications and that stimulants have been shown to improve performance on attentional measures in children with ADHD [30], it is possible that differences between NS and TD groups on Auditory Attention and Inhibition scores may be even larger without the effect of stimulants. This evidence concerns the gene PTPN11 and attention deficit-hyperactivity disorder.