Fig. 1.

A) Experimental visit. At 10:30, subjects completed the Working Memory (WM) task at Session 1, followed by a short break. Next, subjects were randomized to one of three nap interventions (AW, QW, Nap). At 15:30, Session 2 WM testing began. B) The Operation span WM task. The WM task contained nine practice and 20 test trials. The nine practice trials were not counted towards the subjects’ final score. Subjects viewed a serial visual display of letters and math problems. They were asked to hold the letters in memory while simultaneously determining if the simple math problems were correct or not. This was followed by a response period where subjects were asked to type the letters in the previously viewed order.