Eating popcorn and other snacks could make cinema viewers immune to advertising, according to a new study published in the Journal of Consumer Psychology.

The human brain is capable of remembering advertised brand names because of the role of our lips and tongue, which automatically simulate the pronunciation of certain words and phrases when we hear them. This helps advertisements as every time we hear the phrase again, the words are subconsciously practiced through what’s known as our ‘inner speech’.

Scientists working at the Cologne University discovered the impact of popcorn on our 'inner speech' when they invited 96 filmgoers to a cinema screening that included a film preceded by a section of advertisements.

Half of the room were supplied with free popcorn, while the other half were given a sugar cube that dissolved instantly in their mouths.

After the screening the participants were given psychological tests to look for reactions to the advertisements at the start of the film. It was found that for those who had been given popcorn, there had been no significant impact attributable to the adverts or the products they advertised.

However, those who had just a sugar cube showed positive results towards the products when they reencountered the advertisements.

"The mundane activity of eating popcorn made participants immune to the pervasive effects of advertising," said Sascha Topolinski, one of the project's leading researchers.

“This finding suggests that selling candy in cinemas actually undermines advertising effects, which contradicts present marketing strategies. In the future, when promoting a novel brand, advertising clients might consider trying to prevent candy being sold before the main movie."

Whether the study will have any impact on advertising strategies for cinema operators is unclear, but the results of the test certainly provide food for thought when considering how best to capture the attention of cinemagoers before their film begins.