“No chewing gum” is a standard classroom rule. But to feed your addiction, you hide it in the back of your mouth or under your tongue, keeping your mouth sealed shut.

But could your test scores blow your cover?

According to a study published in the journal Appetite, it’s possible.

University students who chewed gum before taking tests performed significantly better in the first half hour of testing than those who didn’t chew gum.

The study found that chewing gum led to an overall increase in cognitive functioning, particularly working memory, episodic memory and speed of processing, but only when gum was chewed prior to taking a test, not during. The effect was strongest just when a person finished chewing gum and only lasted for about 20 minutes afterward.

But just because you pop a piece of bubble gum before your next big test, doesn’t necessarily mean you will ace it.

The study also found the cognitive benefits of chewing gum last for a limited amount of time. The gum chewers performed significantly better in the first 30 minutes of the test as opposed to those who didn’t chew gum. In fact, those who chomped on gum remembered 25 to 50 percent more than people who did not chew gum. However, during the second half of the test, the gum chewers did not have a cognitive advantage over the non-gum chewers.

More research is needed to determine the exact reasons for this boost in brain power, but scientists have a few ideas. One theory suggests chewing leads to an increase in arousal and alertness, and this arousal lasts for a short period of time after you finish chewing.

So next time you think you need a quick brain boost, chomping on a piece of gum may do the trick. Just make sure to chew it before your big test.