Cola Brains

Cola Brains

For over fifty years, Coke and Pepsi have spent billions trying to out-market each other. But a new brain study suggests that one brand has much deeper effects.


Branding in the brain. I'm Bob Hirshon and this is Science Update.

Could a marketing campaign leave a footprint in the human brain? Maybe so, according to neuroscientist P. Read Montague and his colleagues at Baylor College of Medicine in Houston.

They took brain scans of volunteers drinking cola through a tube. Showing them a Coke can while they sipped, but not a Pepsi can, triggered a reaction in certain brain areas—ones used to change behavior based on emotion. This was true regardless of which brand the volunteers said they liked.


There's no such thing as just "what does it taste like?" "What does it taste like?" is a function of the context in which it's tasted and other variables that compile in, and it really changes what you think you like.

Montague says the Coke label also influenced people's choices in taste tests—even though the colas they were given were identical. I'm Bob Hirshon for AAAS, the Science Society.

Making Sense of the Research

Advertisers spend huge sums of money trying to change the way we think. Montague's team decided to look directly at the brain, to find out if a brand name alone could actually produce an observable reaction.

To do this, they had to establish a difference between taste preference and brand preference. First, they conducted a blind taste test, in which their volunteers tasted unlabeled cups of Coke and Pepsi. They found that people's preferences in the blind taste test didn't necessarily match what they said they bought in the store. That suggests taste alone wasn't driving their preferences.

Next, the researchers conducted a "semi-anonymous" taste test, in which the volunteers tasted two colas. One was a correctly labeled cup of either Coke or Pepsi. The other was an unlabeled cup, which they were told could be either Coke or Pepsi. In all cases, the colas were really identical (either both Coke or both Pepsi). Yet, while volunteers strongly preferred the labeled cup of Coke, they split about fifty-fifty between the labeled Pepsi and the unlabeled cola, which was also Pepsi! So here, the Coke brand shows a stronger effect on preference then the Pepsi brand.

Finally, the brain scans. Volunteers drank a cola through a straw, while Montague's team looked for activation patterns in their brains. Sometimes, the volunteers saw a brief image of either a Coke or Pepsi label before they started drinking.

Again, the Coke label, but not the Pepsi label, triggered a strong reaction: the activation of several brain areas that weren't involved in simply tasting the cola. These were areas of the brain normally associated with memory, control of actions, and the way we think about ourselves. Is this showing the effect of years of advertising, which connects the Coke brand to all sorts of emotional and sentimental images? If so, then why do nearly as many people strongly prefer Pepsi to Coke? And do other brand names produce a similar effect in the brain? There are many questions yet to be answered, but this study may eventually help explain why two sugary drinks that are almost identical in chemistry can inspire such fierce loyalty.

Now try and answer these questions:

  1. What effect did the Coke label have on the brain that the Pepsi label did not?
  2. What other evidence suggests that taste alone does not determine your favorite cola?
  3. Obesity is epidemic in America, and sugared soft drinks are one of the primary culprits. How might this research help doctors fight obesity?
  4. Suppose both the Coke and the Pepsi labels triggered the same reaction in the brain. What conclusion would you draw?

For Educators

Coke vs. Pepsi: How does your brain react to soft drinks? from U.S. News and World Report, summarizes the Baylor study efficiently.

Neuromarketing: Is It Coming to a Lab Near You? from PBS' Frontline, connects Montague's research to the emerging field of "neuromarketing"—using brain science to develop marketing and advertising.

Soda Contracts: Who Really Benefits?, on the Rethinking Schools Online site, looks at the growing relationship between schools and soda companies, and how this might affect childhood obesity.

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