Pictures of products danced in his head.

There was an Apple iPod, then a black Aeron chair. A coffeepot by Capresso and a washing machine by Dyson. Christian Dior followed by Versace, Oakley, Honda, Evian and Louis Vuitton.

Each icon of commercial design, 140 in all, was projected onto goggles covering the eyes of a 54-year-old, college-educated, middle-class white male.

The volunteer's head was cradled inside a 12-ton medical imaging scanner at the California Institute of Technology, held firmly in place at the focal point of a pulsing magnetic field. The chamber reverberated with a 110-decibel sandblaster roar.

Behind a double-thickness of shatterproof glass, Steve Quartz, 42, and Anette Asp, 28, monitored the flicker of the volunteer's thoughts in color-coded swirls on a computer display.

The two Caltech researchers were investigating the effect of perhaps the most pervasive force in a consumer culture — marketing — on the most complex object in the world: the human brain.

LORI SHEPLER / LOS ANGELES TIMES Marco Iacoboni, right, a UCLA neuroscientist, and Dr. Jonas Kaplan go over the results of a brain scan of registered Republicans and Democrats who were watching campaign ads.

The power of branding

Quartz, director of the school's social cognitive neuroscience laboratory, and Asp, his project manager, were seeking evidence in the subject's brain of an all-but-indefinable quality of fashion and product branding, the subjective essence that makes an object irresistibly cool.

As the magnetic signals hammered the air, the subject's brain told them things that his mind did not know.

Psychologists and economists are using sophisticated brain scanners to tease apart the automatic judgments that dart below the surface of awareness.

In the process, they are gleaning hints as to how our synapses might be manipulated to boost sales, generate fads or even win votes for political candidates.

They have glimpsed how the brain assembles belief.

The why of buy is a trillion-dollar question.

By one estimate, 700 new products are introduced every day. Last year, 26,893 new food and household products materialized on store shelves around the world, including 115 deodorants, 187 breakfast cereals and 303 women's fragrances. In all, 2 million brands vie for attention.

To find profit in so many similar items, marketers try to brand a product on a buyer's mind. Such efforts put the average American adult in the crosshairs of as many as 3,000 advertising messages a day, five times more than two decades ago.

A sea of messages

Children are exposed to 40,000 commercials every year. By the age of 18 months, they can recognize logos. By 10, they have memorized 300 to 400 brands, according to Boston College sociologist Juliet B. Schor.

"We are embedded in an enormous sea of cultural messages, the neural influences of which we poorly understand," said neuroscientist Read Montague, director of the Human Neuroimaging Laboratory at Baylor College of Medicine in Houston. "We don't understand the way in which messages can gain control over our behavior."

That is starting to change. By monitoring brain activity directly, researchers are discovering the unexpected ways in which the brain makes up its mind.

Many seemingly rational decisions are reflexive snap judgments, shaped by networks of neurons acting in concert.

These orchestras of cells are surprisingly malleable, readily responding to the influence of experience.

Moreover, researchers suspect that the influence of marketing does more than change minds. It may alter the brain.

Just as practicing the piano or learning to read can physically alter areas of the cerebral cortex, the intense, repetitive stimulation of marketing might shape susceptible brain circuits involved in decision-making.

These inquiries into consumer behavior harness techniques pioneered for medical diagnosis: positron emission tomography, which measures the brain's chemical activity; magneto-encephalography, which measures the brain's magnetic fields; and functional magnetic resonance imaging, which measures blood flow around working neurons.

"This is a way of prying open the box and seeing what is inside," said psychologist Jonathan Cohen, director of Princeton University's Center for the Study of Brain, Mind & Behavior.

Inside the Caltech scanner, faces flashed before the subjects.

Each one was famous, an easily recognized celebrity marketed as heavily as any designer label.

Each triggered a response in the volunteer's brain, recorded by Quartz and Asp with Caltech's $2.5 million functional magnetic resonance imager (fMRI) and then weighed against the volunteer's responses to a 14-page questionnaire.

Uma Thurman: cool

Uma Thurman. Cool.

Barbra Streisand. Uncool.

Justin Timberlake. Uncool.

Al Pacino. Cool.

Patrick Swayze. Very uncool.

The volunteer's brain cells became a focus group.

In his mind's eye, the celebrities triggered many of the same circuits as images of shoes, cars, chairs, wristwatches, sunglasses, handbags and water bottles.

Barbra Streisand: uncool

For all their differences, objects and celebrity faces were reduced to a common denominator: a spasm of synapses in a part of the cortex called Brodmann's area 10, a region associated with a sense of identity and social image.

"On first pass, there might seem to be nothing in common between cool sunglasses, cool dishwashers and cool people," Asp said. "But there is something that these brains are recognizing — some common dimension."

None of these neural responses comes consciously to mind when a shopper is browsing brand labels.

Much of what was traditionally considered the product of logic and deliberation is actually driven by primitive brain systems responsible for emotional responses — automatic processes that evolved to manage conflicts between sex, hunger, thirst and the other elemental appetites of survival.

Justin Timberlake: uncool

In recent years, researchers have discovered that regions such as the amygdala, the hippocampus and the hypothalamus are dynamic switchboards that blend memory, emotions and biochemical triggers. These interconnected neurons shape the ways that fear, panic, exhilaration and social pressure influence the choices people make.

As researchers have learned to map the anatomy of behavior, they realized that the brain — a 3-pound constellation of relationships between billions of cells, shaped by the interplay of genes and environment — is more malleable than anyone had guessed.

Lattices of neurons are linked by pathways forged, then continually revised, by experience. So intimate is this feedback that there is no way to separate the brain's neural structure from the influence of the world that surrounds it.

In that sense, some people may indeed be born to shop; but others may be molded into consumers.

Al Pacino: cool

"We think there are branded brains," Asp said.

The Caltech experiment, funded with a $1 million grant from the David and Lucille Packard Foundation, seemed to detect a part of the brain susceptible to such influences.

After analyzing test data from 21 men and women, Quartz and Asp discovered that consumer products triggered distinctive brain patterns that allowed them to classify people in broad psychological categories.

At one extreme were people whose brains responded intensely to "cool" products and celebrities with bursts of activity in Brodmann's area 10 — but reacted not at all to the "uncool" displays.

The scientists dubbed these people "cool fools," likely to be impulsive or compulsive shoppers.

At the other extreme were people whose brains reacted only to the unstylish items, a pattern that fits well with people who tend to be anxious, apprehensive or neurotic, Quartz said.

Patrick Swayze: very uncool

The reaction in both sets of brains was intense. The brains reflexively sought to fulfill desires or avoid humiliation.

Charging the circuits

Inside the brain of the 54-year-old male volunteer, the sight of a desirable product triggered an involuntary surge of synapses in the motor cerebellum that ordinarily orchestrate the movement of a hand.

Without his mind being aware of it, his brain had started to reach out.

Brain scanning has opened the possibility of new forms of manipulation, by charting ways for marketing savants to harness neural circuits of reward and desire more effectively.

In Atlanta, a consulting organization called the BrightHouse Neurostrategies Group launched the first neuromarketing company in 2002, promising in a news release "to unlock the consumer mind." The company, whose clients include the Metropolitan Museum of Art in New York, Home Depot, Hitachi and Georgia-Pacific, has conducted experiments with neuroscientists at Emory University in an effort to understand product preferences.

Justine Meaux, the company's director of research, said BrightHouse helped businesses apply neuroscience to marketing, brand development and product innovation.

"A few companies are at the stage where they want to incorporate it into their strategy," Meaux said. She declined to name them.

Scientific ad-vances

In Los Angeles, Quartz and his Caltech colleagues have been negotiating with a marketing company called Lieberman Research Worldwide to find a way to sell brain-scanning services to advertisers.

"Our intent is to develop some type of strategic alliance that would develop tools and perhaps products for marketing-research users, based on the work Steve's doing," said Tim McPartlin, a senior vice president with the company. "It looks extremely useful to us."

At the Open University in Britain and London Business School, researchers have been recording brain activity as shoppers tour a virtual store. The researchers say they have identified the neural region that becomes active when a shopper decides which product to pluck from a supermarket shelf.

In Germany, DaimlerChrysler used brain imaging to assess how young men responded to different car designs. In Japan, researchers at Nihon University and the Gallup Organization used brain scanning to probe customer loyalties to a Tokyo department store.

Others skeptical

Many researchers are skeptical of efforts to commercialize insights into how the brain works.

"Right now, brain scanning, especially at the level of neuromarketing, is to some degree a matter of tea-leaf reading," said George Lowenstein, a behavioral economist at Carnegie Mellon University.

Nevertheless, a consumer group called Commercial Alert sought a congressional investigation of neuromarketing research last year.

"What would happen in this country if corporate marketers and political consultants could literally peer inside our brains, and chart the neural activity that leads to our selections in the supermarket and the voting booth?" asked Gary Ruskin, the group's executive director, in a letter to the Senate Committee on Commerce, Science and Transportation.

"What if they then could trigger this neural activity by various means, so as to modify our behavior to serve their own ends?"

Already, some researchers have experimented with brain scanning as a way to probe how the brain responds to political ads.

Research by neuroscientist Marco Iacoboni at the University of California, Los Angeles, suggests that political beliefs appear to trigger the same malleable circuits of reward, identity, desire and threat.