Did Sen. Barack Obama buy the election of 2008, given that he bypassed public financing and so was able to raise and spend twice as much money as Sen. John McCain?  In 2012, the concern is the high spending by PACs but the playing field is level, both campaigns can raise and spend as much as possible this election and they will; each candidate this year will spend as much as the entire 2004 election, the last time both candidates held themselves to public financing limits.

Communications experts say in a new analysis spending makes no difference; by the time elections come around, people are tuned out and avoid political information that challenges their beliefs anyway. In the last days of the 2008 campaign, people watched a variety of actual ads for McCain and Obama while the viewers' heart rates, skin conductance and activation of facial muscles were monitored. The results showed that partisan participants reacted strongly to ads featuring their favored candidate, but barely responded to ads featuring the rival candidate.

In comparison, people who didn't favor one candidate over the other showed similar physiological response patterns and intensity to ads for both Obama and McCain. This suggests that partisan participants weren't really paying attention to the ads featuring the candidate they opposed even as they watched them, said Zheng Wang, lead author of the paper and assistant professor of communication at Ohio State University.

"If people are exposed to information in ads regarding a candidate they oppose, they respond by basically tuning out," Wang said. "A lot of research has shown that, behaviorally, we tend to selectively expose ourselves to information that reinforces our existing opinions. But this study further suggests that even when exposed to information, our attention to what is presented is highly selective, as well." 

They used 15 college students (standard for social sciences) who came to Wang's laboratory in October of 2008. They were hooked up with electrodes that measured four physiological responses: heart rate, skin conductance (a way to measure sweating, which is related to how stimulated and alert the person is), and muscle movements around the cheekbone and around the eyebrows. Combined, those physiological responses indicate emotional responses and attention levels, Wang said.

While hooked up to the electrodes, each participant watched 12 campaign ads - six for Obama and six for McCain - while their physiological reactions were recorded. After watching the ads, the students filled out measures of how positively and negatively they regarded Obama and McCain in general.

They say the physiological measures revealed how much the viewers were paying attention and how they were reacting emotionally to ad content that was positive, negative, more emotionally arousing and less emotionally arousing. For example, a lower heart rate suggests that the viewer is taking in information and paying more attention to the ad, while a higher heart rate suggests the viewer is not focused on the ads. The muscles in the face also indicate how much attentional effort a person is making.

In their analysis of the results, they used what they called a dynamical feedback model to see how the different ad factors interacted with the viewers' partisan leanings to influence their physiological reactions over time.

"At any one time, ad viewers' reactions are affected not just by what they are seeing at that exact moment, but also by what came before in the ad," Wang said. "The dynamical feedback model puts it all together to see how people react in a real-time, real-world way."

For supporters of a particular candidate, the feedback model suggests that the positive feelings that viewers have are amplified as they watch an ad for their candidate, Wang said. But for opponents, the feedback effects actually seem to decrease their response over time as they watch the ad - in essence, they tune out, she said. "When we integrate all of the ad message inputs into this dynamical system of the viewer's mind, we find the response of supporters is intensified, while the opponents become nonresponsive."

The results also suggest that it isn't easy to predict how simple ad categories - such as positive ads versus negative ones - will affect viewers. "The ad message is only part of the story because it interacts with how individuals process the ad," she said. "In addition, one negative ad is very different from another negative ad, in terms of their content dynamics and how people react over time. And a 60-second version of an ad can have quite different effects from a 30-second version of the same ad. How people react to ads is a very complex and dynamic process."

Wang co-authored the study with Alyssa Morey, a graduate student in communication at Ohio State, and Jatin Srivastava, an assistant professor at Ohio University. Published in Communication Research.