CLOCK and attention deficit-hyperactivity disorder: Given the central role of WM in the performance across different perceptual timing tasks as suggested by our results, it is an issue of ongoing debate if WM reflects an intrinsic part of a central clock mechanism which is disturbed in ADHD as represented by abnormally fast counting processes (i.e., a faster “internal clock”) or if WM—together with further executive support functions—and perceptual timing share common neurofunctional networks such that timing performance in children with ADHD is confounded by executive dysfunctions (Rubia et al., 2009; Noreika et al., 2013).