(FORTUNE Magazine) – 9

Will a voluptuous babe leaning against a silver sports car entice you to buy it? No need to answer. Marketers now have a way to let your brain talk for you. A powerful scanning technology known as functional magnetic resonance imaging (fMRI) is making its way out of the labs and into marketers' toolkits for studying consumers' emotions and motivations. Essentially a $2.5 million tricked-out version of the MRI machines in hospitals, an fMRI detects the ebb and flow of blood to the brain's centers of pleasure, thought, or memory. Research by Baylor College of Medicine neuroscientist Read Montague suggests that when you like what you're seeing, blood flow increases in certain parts of your prefrontal cortex. This does not mean science has found humankind's buy button, says Justine Meaux, a neuroscientist at BrightHouse, an Atlanta consulting firm; too many other factors intervene between desire and action. "I love wine," she says, "but if you put me in a scanner after I have a big breakfast and show me wine, my brain might not show a preference response."

Even so, companies are beginning to experiment; Ford ran a market test using brain-scan studies in Europe, and Hollywood is interested too. To test viewers' reactions to movie trailers, neuroscientist Steven Quartz of Caltech and Tim McPartlin of L.A.-based Lieberman Research Worldwide have created an fMRI service for filmmakers and plan to offer fMRI studies on everything from logos to packaged goods. Quartz even conducted an fMRI water taste test. The result? While we might think bottled water is cool, he says, our subconscious usually prefers the taste of tap. -- Julie Schlosser