Question

question 9 of 10
what stage is deep sleep, when it is difficult to wake you up?

a. stage 4

b. stage 1

c. rem

d. stage 2

Explanation:

In sleep cycle theory, Stage 4 (also part of slow - wave sleep or deep sleep) is the stage where an individual is in deep sleep and it is very difficult to be awakened. Stage 1 is the lightest sleep stage, REM sleep is associated with dreaming and has different physiological characteristics, and Stage 2 is a transitional sleep stage, not the deep sleep stage with difficulty in awakening.

Answer:

A. Stage 4