A research team asked two groups of testers to sleep in the laboratory for one night. The first group was arranged to sleep late
Most of the second batch of testers have been emotionally inactive for a long time.
as to reduce the total sleep time. The second group was arranged to go to bed early, but was awakened many times during sleep. After the second night, the results showed that the positive emotions of the second group of testers were seriously affected. Their energy level was low, and their positive emotion indexes such as compassion and friendliness decreased. Some researchers believe that being awakened led to the inability of testers to get enough slow wave sleep, which is the key to restoring energy. But some researchers have questioned the credibility of this study.