[Medical Q&A] Will staying up late for a long time affect memory?

Author: Li Cuiluan, deputy chief physician of Shandong Mental Health Center

Reviewer: Mi Guolin, Chief Physician, Shandong Mental Health Center

Experiments have repeatedly confirmed that memory consolidation depends on sleep after learning. If you fall asleep immediately after studying hard for a period of time, it will strengthen the content and memory of what you have learned. Among them, different sleep periods play different roles in memory consolidation. Slow-wave sleep is more important for explicit memory (dependent on the hippocampus), while rapid eye movement sleep (REM sleep) is more important for implicit memory (not dependent on the hippocampus).

In recent years, the results of studying the process of sleep and memory consolidation using electrophysiological and brain functional imaging techniques have shown that hippocampal neurons during sleep can reproduce hippocampal activity during wakefulness, that is, brain activity during sleep transforms newly acquired and encoded information during wakefulness from traces of unstable memories into more stable memory patterns. The essence of this memory consolidation is to restart the processing of new information in the neural circuits that encode it, which is called reactivation or replay. If the reactivation process is strengthened, the effect of memory improvement will be more significant. On the contrary, if the reactivation process of hippocampal neurons during sleep is blocked, memory will be impaired.

Staying up late causes people to lose their slow-wave sleep and rapid eye movement sleep, which has a great impact on the consolidation of both explicit and implicit memory.