HMN 2026: How reading reshapes language processing

Learning to read reshapes how the brain processes language. New research from Baycrest and the University of São Paulo shows that learning to read fundamentally changes how the brain responds to spoken language, even when no written words are present. While previous brain imaging studies have demonstrated that literacy strongly affects how the brain responds to written words, this study is among the first to show differences in brain activity during listening alone.

How learning to read rewires listening

The findings confirm that as people learn to read, they develop a skill known as phonemic awareness, the ability to hear and manipulate the individual sounds that make up spoken words, a core foundation of reading. The study shows that learning to read improves how the brain processes spoken language by increasing sensitivity to these component sounds. This, in turn, strengthens short-term verbal memory, supporting the ability to learn complex skills and manage the cognitive demands of daily life.

The work is published in the journal Cortex.

“This study helps us understand how brain regions involved in analyzing the sounds of spoken language operate independently of meaning,” says Dr. Jed Meltzer, Senior Scientist at Baycrest’s Rotman Research Institute and senior author of the study, titled “Literacy modulates engagement of the right inferior frontal gyrus in phonological processing of spoken language,”

“Even though this level of analysis is not required for everyday communication, reading is a fundamental skill that unlocks more sophisticated cognitive abilities that extend far beyond reading itself,” Dr. Meltzer adds.

Who participated and what they did

Participants were drawn from two groups of older adults: individuals who were just beginning to learn to read later in life and were considered functionally illiterate, meaning they were unable to read a text for comprehension despite knowledge of the alphabet and some basic words; and more educated older adults who have been reading since childhood.

Participants in both groups listened to a story and pressed a button whenever a specific target word (“water”) was heard, while their brain activity was measured using magnetic resonance imaging (MRI). The story was presented partly in Portuguese, the participants’ native language, and partly in Japanese, a language entirely unfamiliar to them. Both versions were recorded by the same speaker, a fluently bilingual teacher from São Paulo’s Japanese-Brazilian community.

What the brain scans revealed

Although participants in both groups performed well when listening in their native language, their performance and brain activity patterns differed markedly when listening to the unfamiliar language. Individuals who had learned to read earlier in life showed greater engagement of a key region in the right hemisphere of the brain during the more challenging listening task.

While the left hemisphere is dominant for language processing, the right hemisphere becomes more involved when tasks are more demanding. The findings suggest that this right-hemisphere recruitment reflects a learned skill acquired through reading.

Main study findings:

• Learning to read changes how the brain processes spoken language, increasing sensitivity to the individual sounds within words.
• Early literacy is linked to greater right-hemisphere brain engagement during challenging listening tasks, indicating that learning to read supports more advanced phonological processing under cognitive strain.
• Learning to read not only provides the obvious benefits of literacy, but also fundamentally shapes how the brain processes language in general and likely improves our ability to handle the cognitive challenges of modern life.

These results may inform future research on maintaining brain function in older adults. Literacy and lifelong learning could play a role in strengthening cognitive resilience, supporting how the brain adapts to increasing challenges with age.

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