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Science/Technology

Magnetic attraction

Pamela Johnsonby Pamela J. Johnson
BCI researchers use the functional magnetic resonance imaging scanner to study the human mind. (Photo/John Livzey)
Photo: BCI researchers use the functional magnetic resonance imaging scanner to study the human mind. (Photo/John Livzey)

“Danger! This magnet is always on!” reads a sign on the door to the functional magnetic resonance imaging (fMRI) machine in the Dornsife Neuroimaging Center and the Brain and Creativity Institute (BCI), housed at the USC Dornsife College of Letters, Arts and Sciences.

A list of what not to bring or do near the apparatus warns against pacemakers, metal implants, metal fire extinguishers, watches, keys, cellphones and, of course, smoking.

“Be careful to remove your glasses, hairpins or anything metal at all,” Sarah Gimbel, a postdoctoral research associate at BCI, cautioned a young woman who had agreed to be scanned for a research project.

Weighing several tons, the magnet in this scanner has a strength of 3 tesla. It is the most powerful scanner available for clinical use today. Compare 3 tesla with magnets having half the strength that can lift a tractor. The 3-tesla magnet is 60,000 times more powerful than Earth’s magnetic field.

Near the machine, metal items become dangerous projectiles that will abruptly and with great force be pulled out of your pocket or hair, or fly off your wrist. Artificial heart valves are forbidden. You have a bullet fragment in your body from an old war wound? You can’t be scanned.

“Anything in your pockets?” Gimbel asked Laura Driscoll, an international relations senior who took the test for the experience and the $20-an-hour pay. “Hair clips, coins, anything?”

“I have a belt,” Driscoll said.

“Let’s go ahead and take that off,” Gimbel said. “OK, perfect. Leave your shoes at the door and we’ll get you all set up.”

Metal free, Driscoll slipped off her sneakers, entered the scanning room and sat on the scanner bed, where the BCI’s Jonas Kaplan, research assistant professor of psychology, and Christine Tipper, a postdoctoral research associate, began connecting electrodes and a belt to her chest to monitor her heart and breathing rates. They attached electrodes to her foot to measure skin conductance.

When scanning, the machine sounds like the motor of a water pick gone awry — only many times louder. Driscoll was given earplugs and headphones, which muffled the deafening noise of the fMRI but still allowed her to hear instructions from researchers.

Driscoll reclined on a long table extending from the machine, and Tipper placed a USC comforter over her.

“She’s going to be in there for a little over an hour, and she can’t move the whole time,” Gimbel said. “So we try to make them as comfortable as possible.”

A loud whir began and Driscoll disappeared into the doughnut hole of what looked like a stark white spacecraft that is 4-feet deep and 8 feet in diameter.

Driscoll was participating in a study called “Neurobiology of Narrative Framing.” The study brought together University Professor Antonio Damasio, BCI director; University Professor Hanna Damasio, BCI co-director; Mary Helen Immordino-Yang, assistant professor of education, psychology and neuroscience; Kaplan; Gimbel; Tipper; BCI researcher Andrew Gordon; and others from the USC Institute for Creative Technologies.

The researchers are studying people’s neuropsychological reactions to personal narratives. They’re investigating how people are influenced by the way in which events are framed by a narrator and appeal to the listener’s own values, knowledge and experiences.

While Driscoll’s brain activity was scanned and monitored, she read a set of stories in which people talk about a personal moral dilemma or transgression.

For example, there might have been a writers’ strike at a major newspaper. The person in the story, a writer, broke an unofficial societal code to never cross a picket line. The writer did so because she thought of the bigger picture: The First Amendment guarantee of free speech must be upheld.

After reading the narratives, Driscoll was asked whether she thought the person in the story would have acted differently for any amount of money. This showed researchers how deeply felt the beliefs of the narrator came across to Driscoll.

Later, Driscoll answered a questionnaire that revealed her own beliefs about the issues discussed in the stories. The researchers compared her brain activity while each issue was discussed with her written responses to see how they matched up.

“We’re getting a handle on how the brain is processing these narratives and relating how participants respond to the stories with their own values,” Tipper said. “With all of these stories, every person who gets scanned responds differently. For some people, crossing the picket line is absolutely reprehensible. And others would say freedom of speech is more important.”

She added: “So there are these polarizing issues that they’re watching. We’re really utilizing the differences between individuals to get at what it is that makes these sacred values tick in people’s brains.”

In part, quantitative analyses of cross-cultural sacred narrative framing can be used to predict effective framing. The researchers would determine how narratives can be most effective given particulars of the situation, the narrator’s goals and the culture of the listeners. The analysis can be validated through behavioral and neurobiological measurements.

“How are you doing in there, Laura?” Gimbel asked Driscoll.

“OK,” Driscoll replied.

“Excellent,” Gimbel said. “This is going to be the very last round of stories.”

While Driscoll read the last group of stories, Gimbel added, “We always check on them from time to time. People are known to fall asleep in there. It gets pretty cozy.”

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