Scientists Learn More About the Brain by Studying Harry Potter Readers

Chapter 9 of Harry Potter and the Sorcerer’s Stone not only hinted at the young wizard’s promising future as a Quidditch player, but also helped scientists detect the different brain regions activated among story readers.

Carnegie Mellon University scientists took functional magnetic resonance imaging (fMRI) scans of 8 individuals as they read Chapter 9 of Harry Potter and the Sorcerer’s Stone and examined the results for their study published in PLOS One.

The subjects read the text using Rapid Serial Visual Presentation, which meant they read the 5000-word chapter word-by-word, with a screen devoting a half-second to each word. Then, the subjects considered 195 story features for each word, such as the part of speech, the dependency role in the sentence, the number of letters, physical motions, non-motion actions, dialogue, and emotions. From there, the scientists used an algorithm to analyze the activation of each cubic centimeter of the brain for every 2 seconds in which 4 words were shown.

From the results, the scientists constructed a computational model that could distinguish with 74% accuracy which of 2 previously unseen text segments was being read—a percentage they noted was significantly higher than chance accuracy of 50%.

One of study’s findings was that regions of the brain encode different information about the characters in the story.

Physical motion, for example, such as the scenes involving flight were represented in the posterior temporal cortex/angular gyrus, which the scientists noted was implicated in the perception of biological motion. Motion also activated a region in the superior temporal sulcus and left inferior frontal gyrus.

Dialogue, on the other hand, activated regions in the bilateral temporal and inferior frontal cortices.

“It seems like presence of dialog activates the right temporo-parietal junction, a key theory of mind region,” the study authors wrote. “This observation raises an exciting hypothesis to pursue: that the presence of dialog increases the demands for perspective interpretation and recruits theory of mind regions.”

Typically, brain imaging studies focus on 1 aspect of language at a time, so this analysis was unique in examining multiple cognitive subprocesses at a time and also in using a natural environment, the authors stated.

“Whereas previous work has studied some of these correspondences in isolation, the results presented here are the first to examine neural encodings of diverse story information at such a scale and across the brain in a realistic, story reading setting,” the researchers wrote.

The results of the study could potentially be helpful in measuring reading comprehension and diagnosing reading disorders. For example, the authors of the study noted subject-specific reading maps could be used to better understand the cause of a person’s reading difficulties.