It's all coming back to me now: Researchers find caffeine enhances memory

coffee

For some, it's the tradition of steeping tealeaves to brew the perfect cup of tea. For others, it's the morning shuffle to a coffee maker for a hot jolt of java. Then there are those who like their wake up with the kind of snap and a fizz usually found in a carbonated beverage.

Regardless of the routine, the consumption of caffeine is the energy boost of choice for millions to wake up or stay up. Now, however, researchers at the Johns Hopkins University have found another use for the stimulant: memory enhancer.

Michael Yassa, assistant professor of psychological and brain sciences in the Krieger School of Arts and Sciences at Johns Hopkins, and his team of scientists found that caffeine has a positive effect on in humans. Their research, published by the journal Nature Neuroscience, shows that caffeine enhances certain memories at least up to 24 hours after it is consumed.

"We've always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans," said Yassa, senior author of the paper. "We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours."

The Johns Hopkins researchers conducted a double-blind trial; which participants who did not regularly eat or drink caffeinated products received either a placebo or a 200-milligram caffeine tablet five minutes after studying a series of images. Salivary samples were taken from the participants before they took the tablets to measure their caffeine levels. Samples were taken again one, three and 24 hours afterwards.

The next day, both groups were tested on their ability to recognize images from the previous day's study session. On the test, some of the visuals were the same as from the day before, some were new additions and some were similar but not the same as the items previously viewed. More members of the caffeine group were able to correctly identify the new images as "similar" to previously viewed images versus erroneously citing them as the same.

The brain's ability to recognize the difference between two similar but not identical items, called pattern separation, reflects a deeper level of memory retention, the researchers said.

"If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine," 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."

The memory center in the human brain is the hippocampus, a seahorse-shaped area in the medial temporal lobe of the brain. The hippocampus is the switchbox for all short-term and long-term memories. Most research done on memory—the effects of concussions in athletics to war-related head injuries to dementia in the aging population—are focused on this area of the brain.

Until now, caffeine's effects on long-term memory had not been examined in detail. Of the few studies done, the general consensus was that caffeine has little or no effect on long-term memory retention.

The research is different from prior experiments because the subjects took the caffeine tablets only after they had viewed and attempted to memorize the images.

"Almost all prior studies administered caffeine before the study session, so if there is an enhancement, it's not clear if it's due to caffeine's effects on attention, vigilance, focus or other factors. By administering caffeine after the experiment, we rule out all of these effects and make sure that if there is an enhancement, it's due to memory and nothing else," said Yassa.

According to the U.S. Food and Drug Administration, 90 percent of people worldwide consume caffeine in one form or another. In the United States, 80 percent of adults consume caffeine every day. The average adult has an intake of about 200 milligrams—the same amount used in the Yassa study—or roughly one strong cup of coffee or two small cups of coffee per day.

Yassa's team completed the research at Johns Hopkins before his lab moved to the University of California-Irvine at the start of this year.

"The next step for us is to figure out the brain mechanisms underlying this enhancement," he said. "We can use brain-imaging techniques to address these questions. We also know that is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer's disease. These are certainly important questions for the future."

More information: Paper: dx.doi.org/10.1038/nn.3623

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philstacy9
1 / 5 (1) Jan 13, 2014
Returners
3 / 5 (2) Jan 13, 2014
"If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine," 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."


What is different about this experiment from past experiments which showed that caffeine actually inhibited memory retention, in spite of the improvements in alertness?

For example, quick Google search:

http://www.nimh.n...ry.shtml

The article above tested for visual memory, while the one I linked to tested for motor memory and verbal memory. Their conclusion appears to say the caffeine inhibits motor learning and verbal learning. You'll also notice this experiment has a "Double control": Placebo vs sleep vs caffeine. Placebo also out-performed Caffeine.
Returners
5 / 5 (1) Jan 13, 2014
Ooooh wow. A 1/5 rating for pointing out a difference in the results given a similar experiment, which actually had a better control mechanism.

My God you people claim to be scientific, but you're the opposite of scientific.

Had you been scientific, you might have asked the question, "hmm, why did this test find caffeine improved visual memory, while the other test showed it hindered motor, verbal, and touch perception memory?"

You might have considered a different chemical basis for visual perception vs tactile, or you might have considered the possibility of a bias of some sort in one of the experiments, etc.

You didn't even respond, you just did the ninja 1/5 thing and hid.
philstacy9
not rated yet Jan 14, 2014
Who knows what nonsense lurks in the hearts of men?
Captain Stumpy
not rated yet Jan 14, 2014
@Returners
What is different about this experiment from past experiments which showed that caffeine actually inhibited memory retention

from what I can tell, by reading both studies, the Phys.org study is about memory retention specifically, is a double-blind study, and had more testing of the individuals (for levels of caffeine). The individuals were also non-regular users of caffeine.
The NIMH/NIH study didnt say if the 61 participants were non-regular users, the caffeine was administered later, (same amounts, both studies), and was more a comparison of caffeine VS nap.

It was a good question, though... I wonder WHY the differences in the results...
could one have been better organized? Is timing of administration of drugs important?

most everything i read lately RE:caffeine says that it is good for you in small regular doses
We also know that caffeine is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer's
Sinister1812
not rated yet Jan 20, 2014
This is good news then. I usually have one or two cups a day.. But I don't feel like my memory is any better, to be honest.