Tuesday, December 17, 2013

Your Brain on Fiction

Most of us have read a novel or heard a story that changed our life. Neuroscientists have now detected biological changes in the brain caused by fiction that linger, at least for a few days.

“We already knew that good stories can put you in someone else’s shoes in a figurative sense. Now we’re seeing that something may also be happening biologically," says Emory University neuroscientist Gregory Berns.

“Stories shape our lives and in some cases help define a person. We want to understand how stories get into your brain, and what they do to it."

Neurobiological research using functional magnetic resonance imaging (fMRI) has begun to identify brain networks associated with reading stories. Most previous studies have focused on the cognitive processes involved in short stories, while subjects are actually reading them as they are in the fMRI
scanner.

In a recent experiment, Emory researchers focused on the lingering neural effects of reading a narrative. They had Emory undergraduate students read the novel, Pompeii, a 2003 thriller by Robert Harris that is based on the real-life eruption of Mount Vesuvius in ancient Italy. The novel was chosen for its strong narrative and page-turning plot.

The story follows a protagonist, who is outside the city of Pompeii and notices steam and strange things happening around the volcano. He tries to get back to Pompeii in time to save the woman he loves. Meanwhile, the volcano continues to bubble and nobody in the city recognizes the signs.

“It depicts true events in a fictional and dramatic way,” Berns says. “It was important to us that the book had a strong narrative line.”

For five days, the experiment's participants came in each morning for a base-line fMRI scan of their brains in a resting state. Then they were given nine sections of the novel, about 30 pages each, over a nine-day period. They were asked to read the assigned section in the evening, and come in the following morning.

After taking a quiz to ensure they had finished the assigned reading, the participants underwent an fMRI scan of their brain in a non-reading, resting state.  After completing all nine sections of the novel, the participants returned for five more mornings to undergo additional scans in a resting state.

The results showed heightened connectivity in the left temporal cortex, an area of the brain associated with receptivity for language, on the mornings following the reading assignments.

“Even though the participants were not actually reading the novel while they were in the scanner, they retained this heightened connectivity,” Berns says. “We call that a ‘shadow activity,’ almost like a muscle memory.”

Heightened connectivity was also seen in the central sulcus of the brain, the primary sensory motor region of the brain. Neurons of this region have been associated with making representations of sensation for the body, a phenomenon known as grounded cognition. Just thinking about running, for instance, can activate the neurons associated with the physical act of running.

“The neural changes that we found associated with physical sensation and movement systems suggest that reading a novel can transport you into the body of the protagonist,” Berns says.

The neural changes were not just immediate reactions, since they persisted the morning after the readings, and for the five days after the participants completed the novel.

“It remains an open question how long these neural changes might last,” Berns says. “But the fact that we’re detecting them over a few days for a randomly assigned novel suggests that your favorite novels could certainly have a bigger and longer-lasting effect on the biology of your brain.”

Artwork: Human Brain
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