Researchers from Mahidol University in Thailand have reported that even small amounts of caffeine can sharpen working memory. The findings appeared in a study published in Physiology and Behavior and highlight how modest caffeine intake can influence cognitive performance in healthy adults.
In the experiment, twenty five volunteers took part and were split into two groups. Each participant consumed a flavored water beverage containing either caffeine or no caffeine, with the caffeine dose set at fifty milligrams. This amount is roughly equivalent to half a cup of regular brewed coffee or a standard tea serving, a level commonly accessible to many adults in North America.
To establish a baseline, researchers recorded brain activity using electroencephalography while the participants sat with their eyes closed. After this initial assessment, the volunteers completed two cognitive tasks designed to probe different aspects of mental function. Following the tests, the assigned drinks were consumed. About thirty minutes later, the researchers repeated brain measurements and cognitive assessments. The participants then performed a five minute series of exercises, after which a final data collection occurred. A week later, the same protocol was repeated with the groups exchanging drinks, ensuring a cross over design that controlled for individual differences.
The results showed that thirty minutes after ingesting caffeine, there was a notable decrease in alpha wave activity in the brain. This neurophysiological change accompanied improvements in cognitive performance, particularly in tasks requiring fast hand–eye coordination, working memory capacity, and sustained attention. A subjective sense of drowsiness also diminished as alertness increased, suggesting an immediate, if temporary, boost in mental readiness that aligns with everyday experiences of caffeine consumption. These effects were observed under the controlled conditions of this study, and they contribute to a growing body of evidence linking caffeine to short term enhancements in certain cognitive domains.
Researchers emphasize that while the findings are encouraging, they are based on a relatively small sample and a single caffeine dose. The genetics, habitual caffeine intake, and overall health of individuals can influence how caffeine affects cognition. As such, the study offers insight into acute caffeine effects but does not imply universal or lasting improvements for everyone. For people in the United States and Canada who regularly look to caffeine for a mental edge, the message is nuanced: modest caffeine intake may yield temporary gains in vigilance and working memory, but results can vary and long term outcomes depend on a range of factors including sleep patterns, stress, and tolerance. This study adds to the practical understanding of caffeine’s role in daily cognitive functioning and sets the stage for larger investigations across diverse populations.
In summary, the research demonstrates that low doses of caffeine can produce measurable improvements in specific cognitive functions within about half an hour, without requiring large amounts of the stimulant. The observed shifts in brain activity, paired with improved processing speed, memory, and alertness, offer a straightforward explanation for the wakeful benefits many people experience after a morning cup of coffee or tea. The work underscores the value of considering dosage, timing, and individual differences when evaluating caffeine’s impact on mental performance.