More than 90 percent of the world’s population consumes caffeine in one form or another, statistics show. In the United States, about 80 percent of all adults ingest caffeine through food, drink or medicine on a daily basis. This moderately powerful stimulant generates increased activity in the central nervous system, lifting energy, improving mood and possibly boosting a person’s ability to focus and concentrate. In addition, there is evidence to suggest that caffeine can help increase longevity and reduce cognitive decline.
But caffeine can cause jitteriness when consumed in excessive amounts. People who use it frequently become psychologically dependent on caffeine, to the point that they feel like they need it to get through the day. Medical experts agree that children in particular should avoid taking caffeine in anything more than small doses. The drug’s stimulating effects can easily overpower their fragile young nervous systems, leading to anxiety attacks, insomnia and hyperactivity.
All in all, caffeine possesses a mixed bag of positive and negative characteristics. But few suspected it might have a positive effect on memory, which is why a recent study carried out at Johns Hopkins University is creating so much buzz.
Caffeine, Pattern Recognition and Memory
Researchers at JHU’s Krieger School of Arts and Sciences divided volunteers into two groups. Those in the first group were given 200 milligram caffeine tablets, while those in the second received placebos. A few minutes before swallowing these pills, study participants were asked to observe a series of patterned images, and to do their best to commit what they had seen to memory. After taking the pills, volunteers’ caffeine levels were measured at regular intervals over the next 24 hours, to make sure the caffeine tablets were being properly dissolved and released into their bloodstreams — and to make sure no one was cheating the test by consuming extra caffeine on their own.
After a full day had passed, the two groups of volunteers were brought back in and asked to look at a new series of images. Some of these were repeats from the day before, some were entirely different and others were different but similar to the images from the original sequence. In comparison to the control group, it was found that volunteers who had been given caffeine tablets were able to do a better job of correctly identifying the pictures they had been shown the day before. Those who had taken the placebo, on the other hand, had a difficult time discerning the difference between the repeated images and those with a similar appearance.
Pattern recognition after a time delay is directly related to long-term memory. According to the sponsors of this study, the enhanced ability of the caffeine-using group to remember repeated images would not have been possible unless the brain circuits responsible for memory had been working more efficiently than normal. If the caffeine tablets had been given to the volunteers before they had been shown the original images, the improved mental performance could have been credited to caffeine’s ability to heighten concentration and focus. But because the caffeine was administered after the initial image observations, the researchers assert that improvements in memory are the only possible explanation for the disparity between the caffeine- and placebo-consuming groups.
This conclusion is logical, but it may be a bit premature. If the volunteers in the experiment only attempted to commit the original images to memory when they were actually looking at them, then the interpretation favored by the Johns Hopkins researchers would be hard to dispute. But if study participants continued to replay the images they had seen over and over in their minds in the hours after their first exposure, another explanation is possible. The caffeine circulating through their bloodstreams may have helped them focus on that task by boosting their energy and putting them in a better frame of mind for learning. Caffeine’s overall effect on mental functioning is subtle and complex, and until further experiments are carried out, it cannot be said for sure that memory improvement is the only explanation for these interesting new results.
Adults and Caffeine: A Positive Relationship?
The amount of caffeine given to the volunteers in the Johns Hopkins study was relatively modest. In fact, it almost matches the average daily consumption of American adults who consume coffee, tea, soda, chocolate or medications that contain this ubiquitous substance. So if further research verifies these new findings, few people would need to dramatically increase their caffeine intake in order to benefit from its memory-enhancing effects.
Given its other protective capacities, caffeine may in fact do more good than harm when consumed in reasonable quantities. Its addictive potential cannot be ignored, and young people would still be wise to reject it. But for adults who plan to consume it anyway, it may give them comfort to know their favorite stimulant might actually be helping them in ways they never would have imagined.