Power naps intend to restore alertness, performance, and learning ability.[4][5] A nap may also reverse the hormonal impact of a night of poor sleep or reverse the damage of sleep deprivation.[6] A University of Düsseldorf study found superior memory recall once a person had reached 6 minutes of sleep, suggesting that the onset of sleep may initiate active memory processes of consolidation which—once triggered—remains effective even if sleep is terminated.[5]