- Researchers in Baltimore, Maryland, carried out tests on 100 people
- Showed them a series of images which they had to remember
- Then gave some participants 200mg of caffeine – the same as a strong cup
- Those who took dose could remember pictures more clearly the next day
A cup of coffee can help boost memory, scientists have found.
Researchers found a 200mg caffeine pill, equivalent to a strong mug of coffee, taken a short time after a learning session can improve people’s ability to recall images.
Study participants were asked to identify pictured objects as either outdoor or indoor items. They were then given either the tablet or a placebo five minutes later.
Saliva samples were taken beforehand to measure their caffeine levels and again one, three and 24 hours after they took the pill.
When they returned next day, the participants were shown some of the same pictures, mixed in with other similar images plus some random ones.
Both groups were able to correctly identify pictures as ‘new’ or ‘old’ – but those who took the caffeine pill were more accurate at distinguishing the ‘similar’ alternatives.
Those who received the placebo incorrectly identified these as the ‘old’ originals.
The results, generated from the study of 100, were published in the journal Nature Neuroscience.
The research was carried out at Johns Hopkins University, Baltimore, Maryland, before the lab moved to the University of California, Irvine, at the start of the year.
Neurobiologist Dr Michael Yassa said: ‘We have always known 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.
‘We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours.’
The brain’s ability to recognise the difference between two similar but not identical items, called pattern separation, reflects a deeper level of memory retention, the researchers said.
Dr Yassa said: ‘If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine.
The memory centre in the brain is at the front in an area known as the hippocampus. Until now, caffeine’s effects on it had not been examined in detail. Of the few studies done, the general consensus was the stimulant has little or no effect on long term memory retention.
The research is different from earlier experiments because the subjects took the caffeine tablets only after they had viewed and attempted to memorise the images.
Dr Yassa said: ‘Almost all prior studies administered caffeine before the study session, so if there is an enhancement, it is not clear if it is 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 if there is an enhancement, it is due to memory and nothing else.’
According to the US Food and Drug Administration, 90 per cent of people worldwide consume caffeine in one form or another.
The average adult has an intake of about 200 milligrams, the same amount used in the study, or roughly one strong cup of coffee or two small ones a day.
Dr Yassa said: ‘The next step for us is to figure out the brain mechanisms underlying this enhancement. We can use brain imaging techniques to address these questions.
‘We also know caffeine 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.’
The caffeine induced improvement was not seen with smaller doses of caffeine or when caffeine was given an hour before the picture identification test.
Added Dr Yassa: ‘Caffeine enhanced performance 24 hours after administration. We conclude caffeine enhanced consolidation of long term memories in humans.
‘Future experiments should be conducted to understand the mechanisms by which caffeine can potentiate memory. Given the widespread use of caffeine and the growing interest in its effects both as a cognitive enhancer and as a neuroprotectant, these questions are of critical importance.’
Taking caffeine tablets is known to increase alertness. The stimulant speeds up the central nervous system and provides a quick surge of energy.
It also blocks the body from sending signals of tiredness or fatigue, which may make it easier to stay awake.
Source: Mail Online
