Caffeine is one the world’s favorite productivity fuels and in many countries people choose a caffeinated drink, mainly coffee, to ignite the day. Although some people rightly worry about over-consuming the stuff, findings of a new study suggest that a moderate daily dosage may enhance our memory.
The research carried out at Johns Hopkins University indicates that caffeine can help the brain retain information we study during a period of up to 24 hours subsequent to consuming it. Participants were asked to study images presented to them and five minutes later received either a placebo or a 200-milligram caffeine tablet, which is the average daily intake of caffeine in various forms for 80 percent of adult Americans. Before taking the tablets, salivary samples were taken to measure existing caffeine levels. New samples were taken one, three and 24 hours afterwards. The following day, participants were presented them with a new set of images consisting of repeats, new additions or similar ones, and asked to recognize images they had looked at the day before.
It was found that the participants of the caffeinated group were more capable of telling which images were similar to the ones they had viewed, instead of mistaking them as being the same. The researchers call this kind of ability "pattern separation," that is, being able to recognize difference between similar items. It is a marker of a deeper level of memory retention.
Studies on the pros and cons of caffeine consumption are nothing new, but this research represents a departure from the usual methodology, where subjects are given caffeine before the study sessions.
"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," says the leader of the research team, Michael Yassa. "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."
The study does not mean, however, that we should binge on coffee in an effort to develop a super memory. Yassa tells us that a higher dosage (300 mg) was not found to be more effective than 200 mg, and it can come with side effects such as jitteriness, headaches and nausea.
Yassa adds that the findings, which are based on a single memory test, do not suggest that caffeine intake will make our memories generally better. What the new study does suggest is that caffeine can help us retain the memory of something in the period when we are likely to forget it – the "forgetting curve" – which is a critical period over the first few hours or first day following the moment of exposure to the information.
"The next step for us is to figure out the brain mechanisms underlying this enhancement," Yassa says. "We can use brain-imaging techniques to address these questions. We also know that caffeine is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer's disease. These are certainly important questions for the future."
The results of the research were published in the journal Nature Neuroscience.
Michael Yassa runs us through the findings in the video below.
Source: John Hopkins University
