A two - week study of 48 volunteers, aged 21 to 38, showed that in just a few days, the constant sleep shortage reduced their mental abilities, including alertness and reaction time.
تراوح معدل ساعات النوم عند جميع المشتركين بين سبع وثماني ساعات كل ليلة ،‏ ولكنهم في الدراسة قُسّموا الى اربع مجموعات .‏