What is the central idea of the first section:when and how often do we dreams?

Answer:
People dream every night during a sleep cycle called REM sleep.
Explanation:
It would be helpful if you added the article, but luckily I was also doing the question on I-ready and got it correctly.
Answer:
People dream every night during a sleep cycle called REM sleep.
Explanation:
REM sleep is a rapid eye movement that people experience when they sleep at night. While people are sleeping they move their eyes quickly in different directions as if they were awake. Scientists say that dreams ussually occur during REM sleep. Scientists also say that there are three different stages when we sleep. The first one is when we close our eyes, the second one is when your body gets ready to sleep deeply and the last stage is when you are in a deep sleep. If somebody wakes you up during stage three you will feel disorientated.