Coke versus Pepsi: It's all in the head

The preference for Coke versus Pepsi is not only a matter for the tongue to decide, Samuel McClure and his colleagues have found. Brain scans of people tasting the soft drinks reveal that knowing which drink they're tasting affects their preference and activates memory-related brain regions that recall cultural influences. Thus, say the researchers, they have shown neurologically how a culturally based brand image influences a behavioral choice.

These choices are affected by perception, wrote the researchers, because "there are visual images and marketing messages that have insinuated themselves into the nervous systems of humans that consume the drinks."

Medicalnewstoday.com