For decades, there was a standard technique for measuring the effectiveness of television advertisements: the focus group. Gather a group of people into a room, show them an ad, and ask survey questions about what they saw. Focus groups, of course, have evolved since the early days on Madison Avenue. Many researchers now use dial-testing techniques that register the intensity of positive and negative reactions to ads in real time, rather than merely asking people for their opinions. But even these methods have limitations. Factors such as unreliable memory, self-deception, and the desire to “please the researcher” can lead to responses that do not accurately reflect the myriad ways ads engage viewers.

Moran Cerf, an assistant professor of marketing at the Kellogg School and a neuroscientist by training, thinks neuroscience can get around some of these problems—a proposition he and PhD student Sam Barnett have been putting to the test.

“People often answer questions the way they want to be rather than the way they actually are,” explains Cerf. “People buy clothes that the skinnier version of them would wear. They buy gym memberships like a person who would exercise daily, and they set the alarm not thinking that they will push the snooze button multiple times before they actually wake up.”

A technique like EEG, however, can expose discrepancies between what the conscious brain wants (or says it wants) and what the unconscious brain actually demands.

Your Brain on Ads

In a study conducted during the Super Bowl by Cerf and Barnett (and still being written up), multiple participants, mostly from the Kellogg community, watched the game while wearing EEG caps that record electrical signals from the brain. Additionally, participants’ facial reactions were recorded with a video camera so that their emotions could be later analyzed, and they answered survey questions in real time. (Many of the survey questions were modeled after the Kellogg 2015 Super Bowl Ad Review questions.) The researchers wondered: How effective, memorable, attention grabbing, emotionally stimulating, and engaging did these participants find the ads?

In many cases, all three data-collection methods led to similar conclusions. However, the neural data often provided additional insights. For example, some ads triggered particularly strong momentary responses in the brains of women versus men, or vice versa. Other ads stimulate subconscious anxieties or preferences, which can be detected via EEG but are missed by more traditional methods. In other words, the brain sometimes “knew” more than the participants reported on their surveys. (For more insight into some of Cerf’s methodologies, read our longer feature here.)

"We can now help companies figure out the optimal length to make the ad for the Super Bowl, potentially saving millions of dollars."

Such highly accurate customer insights offer obvious benefits to advertisers. They could use the technology to determine how frequently an ad must be run, for instance, to be most effective. They could also use the technology to determine when an ad should be run. “We can determine which ads should be placed in a sequence together to maximize engagement,” says Barnett.

And is that extra-long spot really a good idea? “If a Super Bowl ad costs a million dollars for 10 extra seconds, and I can now look at your brain and see that the same ad—whether it is 30 seconds or 20 seconds—is just as memorable, emotional, and engaging, then we can now help companies figure out the optimal length to make the ad for the Super Bowl, potentially saving millions of dollars,” says Cerf. Identifying the most and least engaging moments in an ad is key to this process, and the real-time nature of EEG makes this possible.

That Extra Ten Percent

The technique even has the potential to change how advertisers talk about abstract concepts like engagement or emotion. “When someone wants an ad and they say, ‘give me something that is emotional and engaging,’” Cerf says, “we can now talk in numbers rather than more fluid terms. We can say this ad gets you a memorability score that is 20 percent higher than another ad. If you would rather sacrifice memorability for an emotional narrative, then you might want to go for an ad that is ranked high on a different dimension.”

There are, of course, limitations to using neuroscience techniques. They are still relatively expensive (EEG systems cost tens of thousands of dollars), and they require technical expertise that does not exist in many companies. It can also be a challenge for leaders to convince people within their organizations to make use of neuroscience at the expense of what they have used for decades before.

Still, neuroscience may offer the most accurate measure of ad effectiveness there is. “Listening to people will always give you a high level of accuracy,” Cerf says, “but looking at their brain gives you this extra 10 percent.” For big companies investing in mega-advertising events, the payoff may be worth it.