Obese adults can imagine the smells of various kinds of food, researchers claim. Reuters

Popcorn is a staple of many movie-going experiences. But there’s a reason advertisers might not want us stuffing our mouths with handfuls of popcorn during a movie -- and it’s not because of the crunch. According to a recently published study in the Journal of Consumer Psychology, chewing popcorn in a movie theater actually makes advertising ineffective.

Researchers at the University of Wuerzburg in Germany wanted to know whether eating popcorn while watching advertisements affected how much information about a product moviegoers retained. The researchers found that eating popcorn disrupted the way we process and remember brand names. Or, as the Guardian cited researcher Sascha Topolinski as saying, the popcorn poppers became “immune to the pervasive effects of advertising.”

In their study, titled “Popcorn in the cinema: Oral interference sabotages advertising effects,” the authors noted that “advertising might be futile under ecological situations involving oral interference, such as snacking or talking, which ironically is often the case.”

The Guardian reported that when we view a word like the name of a brand, our lips and tongue automatically simulate the pronunciation of that name when we first encounter it. And whenever we come across that word again, our mouth subconsciously practices how to say it. Marketers use this to their advantage to get us to remember their products.

“Recent basic research has shown that the underlying mechanism of mere exposure for words, in turn, is the training of sub-vocal pronunciation, which can be obstructed by oral motor-interference,” the researchers said in their study.

To test this, researchers from the university devised an experiment involving 96 participants watching a movie at a cinema. According to the Guardian, one-half the people were given free popcorn to munch on throughout the movie and its preceding advertisements, and the other half were given sugar cubes to suck on, which didn’t last very long.

At the end of the movie, researchers noted who remembered what from the advertisements. They found that those who were eating popcorn didn’t remember a thing, while those who were given mere sugar cubes showed psychological responses to the brands they saw in the ads at the beginning of the film.

This new study appears to stands in contrast to research published this year that found that chewing -- in this case gum, not popcorn -- actually improved concentration. Scientific American reported in March that a study in the British Journal of Psychology found chewing gum increased the flow of oxygen to the part of the brain that controls attention. More oxygen to the brain equals heightened alertness and improved reflexes.