The research team, led by Daniel Borota of the Johns Hopkins University in Baltimore, notes that although previous research has analyzed the effects of caffeine as a cognitive enhancer, whether caffeine can impact long-term memory has not been studied in detail.
To find out, the investigators analyzed 160 participants aged between 18 and 30 years.
On the first day of the study, the participants were shown pictures of different objects and were asked to identify them as "indoor" or "outdoor" items.
Soon after this task, they were randomized to receive either 200 mg of caffeine in the form of a pill, or a placebo tablet.
The next day, the participants were shown the same pictures as well as some new ones. The researchers asked them to identify whether the pictures were "new," "old" or "similar to the original pictures.