The physiology and psychology of short naps Neuroscience supports the claim that brief naps can reliably improve cognitive performance. A 10–20 minute nap boosts alertness and executive function by allowing the brain to clear adenosine and partially transition through light sleep without slipping into deep slow-wave stages that cause grogginess. Naps also modulate mood—raising positive affect and lowering irritability—through shifts in neurotransmitter balance and stress-hormone regulation. For shift workers, students, and parents, tactical naps often translate into fewer errors, faster reaction times, and better emotional regulation.