As the 2012 presidential race heats up, candidates will be on the air trying to win your vote. But inadvertently, they may just convince you to buy a new car or change your brand of toothpaste.

At least that's the implication of a new study, forthcoming in the Journal of Consumer Research, which found that people are more receptive to advertising when it follows a televised speech or debate by a politician they agree with. In fact, whether we're persuaded by commercials or marketing depends to some degree on the context in which we encounter it.

While we like to think ourselves as objective -- evaluating information on a case-by-case basis -- the truth is that context matters a lot. Are we in a good mood or a bad mood? Is it sunny or rainy outside? Are we hungry or full? These are all factors that can affect how we process and interpret information.

In the study, authors Allison Jing Xu of the University of Toronto and Robert S. Wyer Jr. of Chinese University of Hong Kong looked specifically at one factor: our mindset. Previous studies have found that certain types of mindsets can be induced experimentally -- and that these attitudes or moods then determine how we perform on subsequent tasks. For instance, asking people to determine which of two animals is heavier can activate a "which to choose" mindset; later, asked to choose between buying two products, a person may not even consider the option of not buying anything.

For their experiment, the authors induced one group of undergraduate students with a "bolstering" mindset and a separate group with a "counterarguing" mindset. The authors then had the students in each condition watch ads for two vacation destinations. The outcome was striking: Students in a bolstering mindset found the vacation spots far more appealing than the students in the counterarguing mindset.

The same held true when looking at political messages. They subjected subjects to either 10-minute speeches by Barack Obama or John McCain on economics from the 2008 campaign or a 10-minute clip of a 2008 debate between the two. (Apparently, federal testing guidelines allow this, despite its obvious cruelty.) After these political clips, the subjects were then shown a speech by the president of Toyota given after the company's vehicle recall, and a TV ad for Toyota.

Here, they found that Republicans, Democrats and Independents had different reactions to the Toyota advertising depending on what political material they had watched previously. A Republican who had watched a clip of Obama speaking seemed to be in a counterarguing mindset, and thus reported a lower opinion of Toyota. Similarly, a Democrat who had watched John McCain reported a lower opinion of Toyota. But a Republican who watched McCain and a Democrat who watched Obama both gave better ratings to Toyota -- apparently, these people were bolstering.

Independents, meanwhile, were relatively unmoved by the speeches, but the debates put them in a counterarguing mindset -- presumably because they didn't like watching politicians fight and disagree. After watching the debate clip, their opinions of Toyota were lower than those of Republicans and Democrats who'd watched the debate.

Televised political debates, and major political addresses, can draw fairly large audiences. In 2008, over 63 million viewers watched the second presidential debate between Barack Obama and John McCain, and nearly 70 million people watched the vice presidential debate between Sarah Palin and Joseph Biden.

These debates may or may not change many minds. But consumers might want to watch out for what they do to our spending patterns.