“Neuroplasticity” is more than a buzzword—it's the brain’s ability to grow, and change. But it’s easy to associate this adaptiveness with kids, for whom the entire world is new, rather than adults, who have already seen it all. Just how much can the adult brain change? A lot, suggests a new study. As New Scientist’s Anil Ananthaswamy reports, it took just six months to make significant impacts on the brains of adults who learned to read for the first time.
A group of cognitive scientists wondered how cultural experiences—ones that influence people’s lives, but not necessarily their genes—affect the human brain. So they honed in on how reading affects the brain in adults who never learned how.
The researchers worked with 30 Hindi-speaking adults—about 31 years old on average—from villages near the Indian city of Lucknow. Every participant in the study could not read or write and never attended school. None of them could read more than eight words when the study began.
Twenty-one people were taught to read and write while another nine were not. The people assigned to the reading group worked with a professional instructor who taught them for six months. And over this course of time, their brains underwent some amazing transformations.
To track the changes, the team took brain scans with fMRI machines before and after the experiment while the participants' brains were at rest. People who did learn to read showed changes not just in their cerebral cortex or gray matter, which is thought to be the brain’s main learning center, but also in other brain areas like the brain stem, which controls reflexes and regulates bodily functions, and the thalamus, which processes sensory input and routes that information elsewhere in the brain.
The team thinks that the changes might be explained by the increased motor skills reading requires—after all, the eyes must be trained to look at the text in a specific way, and a previous study has shown that kids with dyslexia who train for 12 hours using a video game that challenges their visual attentiveness show improvements in reading. Both the brain stem and the thalamus contribute to an individual’s ability to pay attention to different stimuli.
This latest study could change the way scientists view dyslexia. Previous studies have shown a connection between the structure and function of the thalamus and dyslexia. These new results suggest that learning to read changes the way the thalamus connects to the rest of the brain, and that in turn could help scientists figure out if disruptions in these connections could cause dyslexia.
The study has some downsides, however. It dealt with such a small sample that it’s hard to know if those results might hold for a larger group of people. And since adults learned to both read and write, it’s not clear if one drove brain changes more than the other. Researchers also noted that the teacher used a “locally established method of reading instruction,” which could make the study challenging to replicate in other areas.
Scientists already know that when kids learn to read, their brains change. So it’s not that surprising that adults’ brains would, too. But the sheer magnitude of that change for adults who learn to read is a reminder that brains are capable of intense change—no matter how old you are.