Answer:
REM (Rapid Eye Movement) Rebound
Explanation:
REM rebound occurs when an individual have deprived oneself of sleep for a long period and hence prevented from experiencing REM. The frequency and time spent in the REM sleep is usual longer compared to when there is no sleep deprivation. In other words time spent at the REM stage is usually above normal.
In the case of Anya, because she has not slept for two night is mostly to have a REM rebound.
