Coffee, the Drink of Happy Words

Caffeine improves word recognition and accuracy if the words are positive

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Need another reason to refill your morning cup of joe? How about reading words faster and more accurately? A recent study found that a small amount of caffeine may enhance your ability to process words with positive connotations.

The study, led by Lars Kuchinke, in the Department of Psychology at Ruhr University Bochum in Germany, aimed to find out what effect caffeine had on how people process words with a positive associations.

The results from this research showed that a bit of extra caffeine may help people process "positive" words faster.

"Enjoy another cup of coffee."

Researchers already knew from past work that the brain processes positive-connotation words more quickly than words with a neutral or negative connotation. But they didn't know if an extra shot of caffeine made a difference to this skill.

So they recruited 66 healthy young adults who were split evenly into two groups. One group was given a 200 mg tablet of caffeine 30 minutes before they participated in the experiment, and the other half were given a placebo. All the participants were right-handed, which was important since processing language occurs in the brain's left hemisphere, and differences in hand dominance may skew the results for hemisphere processing.

All the participants also had normal or corrected vision, no history of mental health conditions and a typical daily caffeine intake (about 1.6 cups of coffee a day). The researchers carefully developed word lists of real words and fake words that were similar in every way except their connotation. (Fake "positive" words were real positive words with vowels moved around.)

Then the participants watched a screen where these words flashed before them on either the right or left side of their field of vision. They had to press a button to say whether the word was an actual word or not.

After comparing the groups and analyzing the results, the researchers found that the participants who had been given the caffeine were able to more accurately and more quickly identify the real words from the fake ones compared to those who didn't have the caffeine – but only with positive words.

There was no difference in speed or accuracy between the groups for words with negative or neutral connotations. The effect was small, but it was not due to chance.

The study was published November 7 in the open-access journal PLOS ONE. The research was internally funded, and the authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
November 20, 2012
Last Updated:
April 11, 2013