For many decades, neuroscientists believed there was a “critical period” in which the brain could learn to make sense of visual input, and that this window closed around the age of 6 or 7.
Recent work from MIT Professor Pawan Sinha has shown that the picture is more nuanced than that. In many studies of children in India who had surgery to remove congenital cataracts beyond the age of 7, he has found that older children can learn visual tasks such as recognizing faces, distinguishing objects from a background, and discerning motion.
In a new study, Sinha and his colleagues have now discovered anatomical changes that occur in the brains of these patients after their sight is restored. These changes, seen in the structure and organization of the brain’s white matter, appear to underlie some of the visual improvements that the researchers also observed in these patients.
The findings further support the idea that the window of brain plasticity, for at least some visual tasks, extends much further than previously thought.