Lack of sleep affects memory function, especially social memory related to recognizing and distinguishing familiar faces. A study from Singapore has found that caffeine intake can alleviate this effect, restoring memory performance to near normal sleep levels.
According to Lianhe Zaobao, the research also points out that caffeine's effects on memory are targeted—it does not cause overall brain overactivity nor does it disrupt normal sleep patterns.
On the 23rd, Yong Loo Lin School of Medicine at the National University of Singapore issued a press release introducing the laboratory study conducted on over 100 mice. The findings have been published in the academic journal Neuropsychopharmacology.
Before the experiment, some mice were given caffeine through their drinking water for seven consecutive days, while the rest formed a control group.
Afterwards, all mice first interacted with a stranger mouse (first round). In the following five hours, some mice were kept awake by gentle touch or environmental disturbance to simulate sleep deprivation, while the rest were allowed to rest normally.
Five hours later, the mice again met either the same or a different stranger mouse (second round). Researchers determined whether the mice could still recognize a “familiar face” by comparing the length of interactions between the two rounds.
The results showed that, without caffeine, sleep-deprived mice spent similar amounts of time interacting with familiar mice in the second round as they had in the first round, indicating that they could not recognize a “familiar face.” In contrast, well-rested mice interacted significantly less, indicating normal memory.
On this basis, researchers further examined the effect of caffeine. They found that among the sleep-deprived mice, those who had consumed caffeine also spent significantly less time with familiar mice, a result similar to that of well-rested mice, indicating a recovery of memory function.
Analysis of the mice's hippocampus showed that sleep deprivation weakens the function of a region called CA2, making the connections among nerve cells unstable, thereby affecting memory formation and retention. After caffeine intake, these changes improved markedly and the related brain regions’ functioning returned to near normal.
The statement noted that caffeine is a common stimulant that blocks the transmission of adenosine receptors at the molecular level. Adenosine accumulates during wakefulness and suppresses brain activity, so caffeine counteracts this effect.
Associate Professor Sreedharan from the Department of Physiology at Yong Loo Lin School of Medicine, who led the research, said the study helps deepen the understanding of the relationship between sleep and memory, and also provides new directions for mitigating the cognitive effects of sleep deprivation in the future.
Dr. Huang Yuwei, first author of the research paper, said sleep deprivation not only makes people tired but also disrupts key memory mechanisms in the brain, and that caffeine can reverse these effects both at the molecular and behavioral level. “This indicates that the role of caffeine may not be limited to just keeping you awake.”
The research team plans to further explore the effects of caffeine on memory consolidation and retrieval, and clarify the causal relationship between the two through interventions in specific neural circuits.