Aid your memory with a coffee

Late nights, countless cups of coffee and too many hours in the library can mean only one thing: exam season is approaching.

As we near the middle of the academic year, the looming dread of exams draws closer. Soon, revision will take over and the sight of the sun will become a distant memory. In this time of need the student brain, overworked and starved of sustenance, will inevitably turn to its greatest ally – caffeine. Now it seems as if our old friend may have hidden benefits.

Better known for its effect on alertness, a recent study by scientists in Baltimore suggests that drinking caffeine after studying could enhance long-term memory. Previous studies showed a link between caffeine and long-term memory in honeybees, but it was unclear whether a similar trend would be observed in humans.

To test their hypothesis, Daniel Borota and colleagues at Johns Hopkins University presented a group of participants with a series of images. Each picture showed a different object, such as a saxophone or four-leaf clover. After seeing the pictures, half the group received 200mg of caffeine, while the other half received a placebo. A day later, the volunteers were shown another series of images. These included some items they had already seen (targets), some new items (foils) and some that were similar to previous objects (lures). The participants were asked to label each image as “old”, “new” or “similar”. Results showed no difference in accuracy when identifying old targets and new foils. This was to be expected because this part of the task was easy. The harder task – identifying lures – was performed significantly better by the volunteers who had received caffeine.

From this, the team concluded that caffeine increases long-term memory consolidation. But how much caffeine is needed to see these effects? To discover the optimal dose, researchers varied the amount of caffeine given to volunteers. They experimented with 100 mg, 200 mg and 300 mg of caffeine. Performance in the tests was no different to placebo when using a dose of 100 mg. caffeine was upped to 300 mg. As a result, it was shown that at least 200 mg of caffeine was needed for a memory-enhancing effect. In real world terms, that’s similar to the amount of caffeine in a grande Americano from Starbucks.

Normally, caffeine is consumed before an exam. To investigate whether caffeine has any benefit after the consolidation process has occurred, the team ran a second experiment. Here, they held off administering coffee until one hour before the test. Under these circumstances, no effect was seen on memory retrieval. Unfortunately, that means downing a cup of coffee before entering Butterworth Hall won’t be much help!

Students should also be wary of drinking too much coffee. Volunteers who were given a higher, 300 mg dose reported side effects from the caffeine. These could negate any benefits of memory consolidation. Yet, as the summer exams approach it is nice to know there may be an advantage to all those coffee breaks. It’s not a waste of time after all – it’s revision!