REM sleep plays a critical role in emotional memory processing|New research links deep sleep to Alzheimer's protein clearance|Melatonin timing more important than dose, says new meta-analysis|Blue light exposure affects circadian rhythm within 3 minutes|Sleep restriction of just one night impairs glucose metabolism|Napping under 20 minutes shown to boost cognitive performance|REM sleep plays a critical role in emotional memory processing|New research links deep sleep to Alzheimer's protein clearance|Melatonin timing more important than dose, says new meta-analysis|Blue light exposure affects circadian rhythm within 3 minutes|Sleep restriction of just one night impairs glucose metabolism|Napping under 20 minutes shown to boost cognitive performance|