When we fall asleep, we dive into a strange universe, sometimes wonderful, sometimes frightening: that of dreams. Some seem ...

A study identified five sleep types that could be linked to mental well-being, bedtime habits and brain activity. The findings could help improve clinical treatments.

Have you ever wondered what actually happens in the brain during sleep? While your body appears still and at rest, your brain remains highly active, carrying out essential processes that keep you ...

You can see it coming in right there, that little spot,” says neuroscientist and engineer Laura Lewis. A remarkably bright pulsing dot has appeared on the monitor in front of us. We are watching, in ...

During sleep, the brain must achieve a delicate balance: disconnecting from sensory input to allow restorative functions, while remaining alert enough to wake if danger arises. How does it sort ...

Coffee can help you stay awake. But what does caffeine actually do to your brain once you're asleep? Using AI, a team of researchers has an answer: it affects the brain's 'criticality'. Caffeine is ...

REM sleep is a stage of sleep when your heart rate increases, your blood pressure elevates, and your brain processes emotions ...

You may feel sleepy after drinking coffee if you have not gotten enough quality sleep. Coffee temporarily makes you feel ...

Sign up for CNN’s Sleep, But Better newsletter series. Our seven-part guide has helpful hints to achieve better sleep. Baland Jalal lay in bed terrified ...

After about age 40, our brains begin to lose a step or two. Each year, our reaction time slows by a few thousandths of a second. We're also less able to recall items on a shopping list. Those changes ...