Professor David Dinges of the University of Pennsylvania School of Medicine led research in a laboratory setting on sleep schedules which combined various amounts of "anchor sleep", ranging from about four to eight hours in length, with no nap or daily naps of up to 2.5 hours.
Profesor David Dinges z University of Pennsylvania School of Medicine vedl výzkum v laboratorních podmínkách, kdy spánkové rozvrhy kombinovaly různá množství "ukotvujícího spánku", od 4 do 8 hodin, s napy v celkové délce až 2,5 hodiny nebo bez nich.