A study of women in India who learned to read in their 30s shows the human brain’s incredible capacity to reorganize and transform itself, researchers said on Wednesday.
Researchers recruited women in India, a country with an illiteracy rate of around 39 percent, to see what they could learn about the areas of the brain devoted to reading. At the start of the study, most of the women could not read a word of their mother tongue, Hindi. But after six months of training, the women reached a level comparable to first grade proficiency.
“This growth of knowledge is remarkable,” said Falk Huettig from the Max Planck Institute for Psycholinguistics, lead author of the study in the journal Science Advances. “While it is quite difficult for us to learn a new language, it appears to be much easier for us to learn to read. The adult brain proves to be astonishingly flexible.”
Specifically, researchers found that the exterior of the brain—known as the cortex, which is able to adapt quickly to new challenges—was not the main area where transformation occurred. Instead, researchers found that reorganization took place deep inside the brain, particularly in the brainstem and thalamus, a walnut-sized structure that relays sensory and motor information.
“We observed that the so-called colliculi superiores, a part of the brainstem, and the pulvinar, located in the thalamus, adapt the timing of their activity patterns to those of the visual cortex,” said co-author Michael Skeide, scientific researcher at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig. “These deep structures in the thalamus and brainstem help our visual cortex to filter important information from the flood of visual input even before we consciously perceive it.”
Researchers found that the more signals aligned in the affected brain regions, the better the women’s reading skills became. “These brain systems increasingly fine-tune their communication as learners become more and more proficient in reading,” Skeide added. “This could explain why experienced readers navigate more efficiently through a text.”
The finding could also have implications for the treatment of dyslexia, which some researchers have blamed on a malfunctioning thalamus. “Since we found out that only a few months of reading training can modify the thalamus fundamentally, we have to scrutinize this hypothesis,” Skeide said.
Co-authors on the study came from India’s Center of Bio-Medical Research (CBMR) Lucknow and the University of Hyderabad.