REM sleep

REM sleep involves periods of heightened physiological activity (eye movement, breathing, heart rate, blood pressure), often linked to dreaming. This discovery revealed critical aspects of sleep cycles and their impact on mental health. The function of REM sleep and dreaming remains a matter of dispute.
 William Charles Dement United States 1952 REM sleep

REM sleep involves periods of heightened physiological activity (eye movement, breathing, heart rate, blood pressure), often linked to dreaming. This discovery revealed critical aspects of sleep cycles and their impact on mental health. The function of REM sleep and dreaming remains a matter of dispute.