Oct. 28, 2011 at 11:36 AM ET
You probably count on your daily jolt of caffeine to wake up your brain and stay sharp all day long. But downing that coffee, tea, cola, or chocolate bar may be giving you a leg up in another unexpected way: It can improve your proofreading skills, according to a new study.
Caffeine seems to enhance performance of some of the brain's complex processes that rely on the right hemisphere, such as extracting meaning from language that's written or spoken, says study author Tad Brunye, a senior cognitive scientist at the U.S. Army Natick Soldier Research, Development and Engineering Center in Natick, Mass. "And you don't need excessively large doses to do so," he explains.
In the study, published in the Journal of Experimental Psychology: Applied, researchers asked 36 college students who consumed low levels of caffeine -- about a half-cup of coffee a day -- to do a "language task." The students were given 5 minutes to read a one-page news story, and needed to identify and correct as many spelling and grammatical mistakes as they found in that time.
Forty-five minutes before taking the proofreading test, students were randomly given a capsule containing one of four doses of caffeine: none, 100 milligrams (the amount found in 8-ounces brewed coffee), 200 milligrams (found in 16-ounces coffee), or 400 milligrams (found in 20-ounces of coffee).
In a second study, researchers repeated the same experiment with 38 college students who consumed higher levels of caffeine each day. The java junkies typically had at least 300 milligrams of caffeine daily, roughly three 8-ounce cups of joe.
Caffeine only seemed to make a difference in the student's ability to spot and fix "complex global errors." These were mistakes in subject-and-verb agreement (for example, billionaire inventor Tony Stark enjoy a lavish lifestyle) and verb tense (for example, customers were misled into believing they had got approved for low interest loans).
The low-caffeine crowd was best at finding and correcting these grammatical goofs at 200 milligrams of caffeine. But it took more in the highly caffeinated -- 400 milligrams -- to achieve the highest detection rates.
Interestingly, caffeine didn't affect the students' skill at finding and correcting misspelled words. And it had no effect on noticing mistakes in words that sound alike, such as weather and whether or seams and seems.
"Individuals who habitually consume caffeine on a daily basis are less likely to benefit from caffeine's performance advantages without upping the dose," Brunye says.
So if you're great at finding the grammatical mistakes that occasionally occur in Body Odd posts, we'll assume your caffeine has kicked in.