Question

Why did they focus on REM sleep?

Answer 1

REM sleep is deemed by some to be the fifth cycle of sleep and is often thought to be the most important of them all because it stimulates parts of your brain that are critical to retaining memories and learning. REM sleep starts about 90 minutes after you fall asleep where you enter into the so-called REM cycle.

Step-by-step explanation:

Answer 2

Usually, REM sleep happens 90 minutes after you fall asleep. The first period of REM typically lasts 10 minutes. Each of your later REM stages gets longer, and the final one may last up to an hour. Your heart rate and breathing quickens.

You can have intense dreams during REM sleep, since your brain is more active.

Babies can spend up to 50% of their sleep in the REM stage, compared to only about 20% for adults.

Step-by-step explanation: