Final answer:
REM sleep may lead to more negative emotions due to the brain's processing and regulation, REM rebound, and conditions like REM Sleep Behavior Disorder (RBD).
Step-by-step explanation:
During REM sleep, we may experience more negative emotions due to the brain's processing and regulation.
REM rebound, which occurs when we are deprived of REM sleep and then spend more time in REM sleep to compensate, suggests that REM sleep is involved in emotional processing.
Additionally, conditions such as REM Sleep Behavior Disorder (RBD) can cause high levels of physical activity and disturbing dreams during REM sleep, leading to negative emotions.
Overall, the regulation and interplay of brain activity during REM sleep can contribute to the experience of negative emotions.