Coffee drinkers are well aware of the positive effects caffeine has on the body: A dose of the stimulant can cause increased alertness, better focus, and even euphoria. On the basis of a new study, scientists at Johns Hopkins University are adding enhanced memory to that list (Nat. Neurosci. 2014, DOI: 10.1038/nn.3623). The team asked a group of participants to study images of objects and then gave members of the group either caffeine pills or a placebo. Twenty-four hours later, the researchers showed the participants another set of images, including the original pictures. People who had taken at least 200 mg of caffeine—the equivalent of 1.5 cups of brewed coffee—correctly identified images as being similar to the originals more often than people who took a placebo. Caffeine enhances a highly detailed type of memory called pattern separation, says team leader Michael A. Yassa, who is now at the University of California, Irvine. “It’s the kind of memory needed to discriminate between, for instance, where you parked your car today versus yesterday,” he says. The researchers don’t yet know why caffeine helps solidify memories, but they suggest it may indirectly increase the brain’s production of norepinephrine, a chemical that aids in memory storage.