Coffee Perks Up Short-Term Memory

Coffee might sharpen your memory, an Austrian study suggests. Researchers at Innsbruck Medical University discovered that 100 milligrams (mg) of caffeine-approximately the amount in one cup of coffee increased activity in the part of the brain that is responsible for short-term memory and improved performance on a test that measures memory function.

The Study

For the study, researchers recruited 15 men between the ages of 26 and 47. On the first day of the study, each man was given 100 mg of caffeine dissolved in water. The following day, they were given just plain water. Other than the water, the men fasted during the two-day study period. Twenty minutes after having their drinks, the men underwent functional magnetic resonance imaging (fMRI), and then were tested to assess their working memory skills.

The fMRI showed that caffeine increased activity in the brain's front lobe, where part of the working memory network is located, as well as in the anterior cingulate cortex, the part of the brain that controls attention. None of the men showed increased activity in this area of the brain when they drank the placebo.

In an accompanying test, the men were presented with a randomized sequence of capital letters and were asked to remember whether the current letter was the same as the letter that had been presented two letters before. They were asked to respond as quickly as possible by tapping response pads with their fingers.

After consuming caffeine, all of the men studied showed a tendency toward improved reaction times on the test, compared with when they had no caffeine, according to the researchers.

The study showed that "a distinct brain area within the working memory network was more activated under caffeine compared to the placebo condition. This is the specific brain region that would be used for short-term memory function," says study author Dr. Florian Koppelstatter, a radiology fellow at the University.

These functions include being able to prioritize information in order to manage tasks efficiently, as well as plan new tasks and deal with stored information, he says. An example of this would be the process of looking up a number in a telephone book, and remembering it so you could dial the number.

How Caffeine Works

Dr. Bruce Rubin, a neurologist at the University of Miami's Miller School of Medicine, says this study sheds new light on how caffeine works on the brain.

He adds that previous research had shown that caffeine improves attention, and that any improved memory function identified was assumed to be the result of better focus-"You have to be attentive to remember.

"But this study showed that caffeine had a direct effect on the networks and processing of the memory," Rubin says.

Koppelstatter says the mechanism by which the caffeine acts on the brain is largely unknown, but is related to how caffeine reacts on the small blood vessels and nerve cells in the brain.

Although some coffee may improve your memory, don't think that drinking more will turn you into an intellectual, Koppelstatter says.

"The positive effects of caffeine don't increase in a linear way," he says, and too much caffeine can make you more anxious, counteracting the positive effects it can provide.

Caffeine, found in coffee, tea, soft drinks and chocolate, is the most widely used stimulant in the world, with a global per-person average of 76 mg a day. Americans consume an average of 238 mg of caffeine daily. Scandinavians have the highest daily caffeine intake-400 mg.