A steaming mug of coffee helps me wake up in the morning. But it can do more than just keep your eyes open. Caffeine may actually boost your memory.

Researchers gathered 160 uncaffeinated adults, people who consumed less than 500 milligrams of caffeine a week. These decaf subjects looked at pictures of various objects, then took either a placebo or a pill containing 200 milligrams of caffeine. That's roughly the amount you'd get from two cups of coffee.

The next day, participants examined a fresh set of pictures: some brand new, some from the previous day, and some that just looked similar to the old images. Both groups could identify new and old pictures equally well. But the caffeinated group was better at correctly labeling images that were similar but not identical. The placebo group tended to mistakenly identify these pictures as the same as the previous day's. The work is in the journal Nature Neuroscience. [Daniel Borota et al, Post-study caffeine administration enhances memory consolidation in humans]

So caffeine does more than help you stay alert. Get the picture? The study subjects did.