The lead author of the study Lee Ryan, UA assistant professor of psychology says that memory is often at optimal levels early in the morning in older adults (over age 65) but tends to decline as the day progresses. Ryan said. Her study tested whether a simple stimulant - caffeine, in this case - would have an effect on this decline.

One group received 12-ounce cups of regular coffee containing approximately 220 to 270 mg of caffeine. A control group drank decaffeinated coffee, which usually has no more than 5-10 mg of caffeine per serving. Ryan said participants could not tell whether they were drinking regular or decaf.

The researchers found that participants who drank decaffeinated coffee "showed a significant decline in memory performance from morning to afternoon." The group who ingested the caffeine showed no decline in performance on the memory tests.

Ryan says the study and its results are not meant to endorse the consumption of coffee or caffeine, stating that other stimulants would probably have worked just as well. All the study participants were regular coffee drinkers. People who do not consume coffee regularly might have experienced negative side effects (shakiness, anxiety, and decreased concentration).

Anyone ready for a hot cup of coffee?