Coffee, beloved of sleep-deprived souls, adds a new virtue to its list of perks: it may help in retaining new memories. According to researchers from Johns Hopkins University and the University of California, Irvine, people who drink a minimum of two cups of caffeine-laced coffee may be better able to form certain kinds of memories than those who do not. Virginia Hughes at National Geographic explains the experiment:
They recruited young adults who don’t usually drink much coffee — less than 500 milligrams of caffeine a week, or about five cups of coffee — and who hadn’t had any before the experiment. The volunteers were shown lots of pictures of objects, such as a seahorse, a basket, and a saxophone, and then asked whether each picture depicted an indoor or outdoor item. Soon after looking at the pictures, the volunteers took a pill containing either 200 milligrams of caffeine (which is equivalent to about two cups of coffee) or a placebo.
The next day, the subjects returned to the lab, where they were shown images and asked to label the ones that were repeats from the day before. Some images were obvious additions, whereas others were trickily similar to the pictures from the day before, only with slight alterations. "For instance," Hughes says, "whereas one of the 'old' pictures was a wicker basket with two handles, one of the 'similar' pictures was a wicker basket with one handle and a blue blanket peeking out from under its lid." The subjects who had taken the caffeine pill proved much more adept at picking out these subtle differences.
Those results didn't change, Hughes continues, when the team gave the subjects the equivalent of about 3 cups of coffee's woth of caffeine (i.e., you won't gain super-human memory skills if you quadruple your caffeine intake). But volunteers who received just one cup's equivalent of caffeine performed no better than those who swallowed a placebo.
Wired elaborates on the findings, and what they mean for coffee-drinkers' potential memory boosts:
This ability to pick up on the subtle differences of the images is known as pattern separation and, according to the researchers, is a good sign of a sophisticated level of memory retention.
"If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine," [study author Michael] Yassa said. "However, using these items requires the brain to make a more difficult discrimination -- what we call pattern separation, which seems to be the process that is enhanced by caffeine in our case."
One caveat that Hughes points out, however: the statistics supporting this study were pretty lackluster. So the jury may still be out on whether coffee does indeed help memory-making, and to what extent. But coffee addicts can still rest easy knowing that the primary premise of drinking—keeping awake and alert—still holds true.