Caffeine has a positive effect on long-term memory, according to a study published in the journal Nature Neuroscience.

The study, led by a team of researchers from Johns Hopkins, found that aside from being a commonly used stimulant, caffeine may  also enhance ones memory.

According to background information provided by the authors, previous studies have not looked at caffeine’s effects on long-term  memory in detail. Moreover, among the studies that were conducted, it was concluded that caffeine had little or no effect on long-term memory retention. “Almost all prior studies administered caffeine before the study session, so if there is an enhancement, it’s not clear if it’s due to caffeine’s effects on attention, vigilance, focus, or other factors,” Yassa explained. “By administering caffeine after the experiment, we rule out all of these effects and make sure that if there is an enhancement, it’s due to memory and nothing else.”

For the study, Michael Yassa, an assistant professor of psychological and brain sciences at Johns Hopkins, and his team recruited  individual who either did not eat or drink caffeinated products on a regular basis and gave them either a placebo or a 200-mg caffeine tablet five minutes after exposing them to a series of images.

In addition, samples of the participant’s saliva was taken to measure the difference in caffeine levels before and afterward. Then,  the following day the researchers tested both groups on their ability to recognize the images they were exposed to the day before.

The results revealed that a greater number of participants from the caffeine group were able to successfully identify the new images  as “similar” to previously viewed images rather than erroneously citing them as the same. “We’ve always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans,” said Yassa, senior author of the paper. “We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours.”