Zhu Y, et al. - Researchers assessed how the dynamic interaction effect of circadian rhythmicity and homeostatic sleep pressure on sustained attention was represented on performance and cerebral responses to working memory (another important element of many neurobehavioral tasks) in 36 healthy subjects with intermediate chronotype. While functional magnetic resonance imaging was performed on the participants, they were asked to perform the Sternberg working-memory task (SWMT) every 2 hr from 10:00 p.m. on the first day to 6:00 a.m. on the second day. A rebound of SWMT reaction time and cerebral responses following the mid-time point of regular biological sleep night was seen. Further proof was obtained, in this study, that sleep loss and circadian rhythmicity have differential impacts on different cognitive tasks.