Question

Alcohol can disrupt parts of your sleep cycle, including your REM (rapid eye movement) cycle. What is the function of REM cycles?

Answer 1

REM cycles are experienced when the brain is storing new information in our brains, hence sometimes we create a new world through dreaming. Alcohol disrupts REM cycles, hence, some people claim to have no memory of the previous night after they pass our drunk. 

Answer 2

I believe the answer is: To help you remember and process information you have learned

REM cycles tend to start within 90 minutes after you fell asleep and would take up around 25% of your sleeping time.

During this period, a process that called as memorization session would occurs and this will help you to keep various information that you receive throughout the day in your long term memory.