Octopuses cycle through two stages of slumber, a new study reports. First comes quiet sleep, and then a shift to a twitchy, active sleep in which vibrant colors flash across the animals’ skin. These ...

During REM sleep, your heart rate increases, your blood pressure elevates, and your eyes move. REM sleep may also be the time when your brain processes emotions and solidifies memories. Your body ...

Hasegawa et al. first used a fluorescence-based sensor to measure dopamine levels in the amygdala of mice as they naturally cycled between wakefulness and non-REM and REM sleep. Dopamine release in ...

REM stands for rapid eye movement — a stage in the sleep cycle when your brain is almost as active as when you’re awake. Getting enough REM sleep is crucial, as it helps you store information and ...

A 2021 phone poll revealed that only 34% of Americans "sometimes" remember their dreams. About 1 in 10 say they "almost always" can, and the same percentage say they "never" do. Explanations for such ...

There are tell-tale signs when you don’t get enough REM sleep. It’s the fourth stage of sleep and it’s crucial for processing ...

Eugene Aserinsky never wanted to study sleep. He tried being a social worker, a dental student, and even did a stint in the army as an explosives handler. He enrolled at the University of Chicago to ...

REM may be the most talked-about part of the sleep cycle, but getting enough of it can still be an elusive quest. You might know by now that it’s important, but maybe you don’t know exactly why or how ...

What new research on the avian brain and REM sleep in birds might reveal about our own dream lives. By Maria Popova I once dreamed a kiss that hadn’t yet happened. I dreamed the angle at which our ...