A 3D map of how the brain responds to words could unlock new ways to understand and treat dyslexia and speech disorders.
Map-making: Researchers at UC Berkeley used functional MRI to measure nine volunteers’ brain activity (using blood flow as a proxy) as they listened to, and then read, stories from “The Moth Radio Hour,” a storytelling podcast which airs on 500 radio stations around the world. The researchers collected volunteers’ brain activity data for reading (one word at a time, to help separate the data) and listening to recordings of the same text, then matched both sets of data against time-stamped transcriptions of the stories.
Language links: The results were then fed into a computer program, which mapped out thousands of words according to their relationship to each other, using natural-language processing. For example, the “social” category includes words like “husband,” “father,” and “sister.” Different categories sparked activity in different parts of the brain: these “social” words were found on the right side, behind the ear. This area also responded most strongly to words that describe people or dramatic events, as well as words that describe time.
The biggest surprise: The researchers concluded that there are a lot of similarities, in terms of brain activity, between reading and listening to stories, says lead author Fatma Deniz. Until now, the assumption was that there would be clearer differences between the two. The findings were published in the Journal of Neuroscience yesterday, with a new, updated brain map due to go live next week (we’ll post a link to it here when it’s published).
Why it matters: The findings could help to build clinical applications for dyslexia, by comparing reading and listening maps for people with dyslexia to controls of people without, according to Deniz. Understanding how the brain processes words could also help build better language decoders, helping patients with language disorders, she adds.