American researchers suggest that companies may streamline their advertising campaigns to be more effective by accessing brain responses of individuals.
UCLA neuroscientists reported using brain data to predict how large populations will respond to advertisements.
Thirty smokers who were trying to quit watched television commercials from three advertising campaigns, which all ended by showing the phone number of the National Cancer Institute's smoking-cessation hotline.
They were asked which commercials they thought would be most effective; they responded that advertising campaigns "A" and "B" would be the best and "C" would be the worst.
The UCLA researchers also consulted experts who work in the anti-smoking field and who have been involved in creating anti-smoking advertisements. These experts agreed that campaigns "A" and "B" were the best and "C" was the worst.
While the smokers watched the advertisements, they underwent functional magnetic resonance imaging (fMRI) brain scans at UCLA's Ahmanson-Lovelace Brain Mapping Center, and the neuroscientists focused on part of the medial prefrontal cortex - located in the front of the brain, between the eyebrows - a region that they have found to be especially important in previous persuasion studies.
The researchers found that activity in the medial prefrontal cortex increased much more during advertising campaign "C" than it did during campaign "A," and somewhat more than it did during campaign "B."
"The medial prefrontal cortex predicted 'C' would be the best, 'B' would be second best and 'A' would be the worst - essentially the opposite of what the experts and the participants told us they thought would happen," said the study's senior author, Matthew Lieberman, a UCLA professor of psychology and of psychiatry and biobehavioral sciences.
"We didn't expect how radically different people's predictions would be from the predictions we made based on their brain activity," said Lieberman, one of the founders of social cognitive neuroscience.
"We had people telling us one thing and this brain region telling us something diametrically opposed."
Initially, Lieberman and first author Emily Falk, an assistant professor of communication studies and psychology at the University of Michigan-Ann Arbor, were concerned when they saw the results from the medial prefrontal cortex.
"We were hoping the brain data would add something to the self-reports of our participants," Lieberman said.
"Given how different they were from one another, we were afraid our brain data might not end up predicting the real-world outcomes at all."
A few months later, after the advertisements had been broadcast, the authors received the call-volume data from the National Cancer Institute's 1-800-QUIT-NOW hotline.
They compared the number of people who called the hotline the month before and the month after each of the advertising campaigns was run. All three advertising campaigns were successful in increasing the number of phone calls to the hotline.
Campaign "A" more than doubled the number of calls, "B" increased the number of calls more than ten-fold and "C" boosted the number of calls a remarkable thirty-fold. (The advertisements were shown in Michigan, Massachusetts and Louisiana.)
Activity in the medial prefrontal cortex predicted which ads persuaded more people to call the hotline significantly better than the smokers' own thoughts about how successful the ads would be.
"If people are making decisions based on what focus groups tell them, here's an important brain region saying, 'No, spend your money a different way,'" Lieberman said.
"If I were deciding on an advertising campaign, I would want to know which ads are activating this region the most - that is where I would want to spend my money."
This new research represents "the first thing you could call a neural focus group," Lieberman said.
One reason focus groups can be misleading, he said, is that people often do not know what motivates their own behaviour.
The 30 smokers in the study were between the ages of 28 and 69; half were female.
With the new study, Lieberman and his colleagues wanted to know whether they could predict not only people's own behavior but use these brain responses to predict how effective advertisements would be throughout the country.
The research has been published in the online edition of the journal Psychological Science.