Researchers from Ruhr University in Germany recruited 66 subjects to attempt to quickly and accurately determine whether or not a string of letter flashing across a computer screen were real words or not. Half of the volunteers took a lactose placebo pill, while the other half took tablets containing 200 milligrams of caffeine (about the same as two or three cups of coffee) 30 minutes before the test.
Turns out the caffeinated subjects were able to spot positive words, such as "happy," more accurately than the negative or neutral words by seven percent. The findings were published last week in the journal PLoS ONE.
Prior research has already shown caffeine may stimulate the central nervous system by increasing the activity of the brain chemical dopamine, which is linked with boosting creativity and impulsivity, writes health website LiveScience.
A study published last year also found that women who drink two or more cups of coffee a day are less likely to get depressed. While it’s not clear why this happens, researchers say it may be linked to caffeine’s effect on the brain’s chemistry. The findings, published in Archives of Internal Medicine, come from a study of more than 50,000 US women.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0048487