If you’re reading this sentence, you have at least some level of literacy. But did you know that learning to read is more than just a skill? When you learned how to parse the letters on the page, your brain was quietly reorganizing itself, not just conceptually, but at the physical level. This is demonstrable in brain imaging, but we can also see it in a person’s response to sentences. Those who have achieved even minimal literacy respond differently to a sentence than those who are not literate. In this sense, these two types of individuals process the world differently. Let’s look closer at what reading rewires in the brain and what those anatomical differences might cost the people involved.
The Mechanics of Reading Inside the Brain
Learning to read is a physical process, not just a mental one. Unlike spoken language, which has existed for as long as our species has possessed vocal cords, reading is too new for our brains to have developed a specific organ dedicated to the task. Thus, the brain takes over this work, building literacy from neurons that were originally developed for other purposes and repurposing the regions built for vision and speech.
Rather than building a system from scratch, the brain undergoes neuronal recycling . This means altering part of the visual pathway, which is responsible for recognizing objects and complex shapes, so that it becomes responsive to letters, too. When scientists imaged the brains of readers and non-readers, the left ventral occipitotemporal cortex (the visual word form area) was visibly more developed in those who read. Like the body building up a muscle to withstand greater loads, the brain grows more neural pathways when a person learns to read.
In addition, the brain’s proportions of white matter and gray matter change when a person pursues literacy. White matter carries signals between brain regions, so in people who can read, white matter tends to be denser because it carries written information across multiple parts of the brain. You read a word, and you might hear it in your mind or visualize an image of what it is. All this requires white matter to transfer this data across multiple brain locations.
Reading and Processing: The Role of Literacy
The muscle comparison from earlier might be more apt than you think. Scientists have found that literate and illiterate brains respond differently to the same sentence, and it’s because their brains are “trained” differently. For instance, even when a person isn’t looking at words, learning to read sharpens how the brain handles visual information within the first 200 milliseconds after seeing something. Their ‘brain muscle’ has been trained to respond more efficiently.
Literacy carries into other areas of cognitive processing, too. A person who can read can inherently take alphabetic information and draw comparisons between sounds, how those letters relate to the ones around them, and how words in a sentence are separable, movable, and flexible. As a result, literate adults generally perform better on tasks that ask them to remove or rearrange elements, and their short-term memories may be more efficient (because reading relies on holding information briefly for context).
While it’s true that the brain is highly adaptable at allowing us to learn to read, those neurons co-opted for the purpose were not sitting there doing nothing. Before literacy developed, that region of the brain was responsible for recognizing and responding to objects and faces. As word recognition takes over a concentrated portion of the left brain hemisphere, that face processing has to shift to the right. The division of labor changes, and though this does not mean that a person has sacrificed something in order to learn to read, it is true that should a person suffer a brain injury, the affected abilities can differ based on literacy.
The brain’s adaptation to accommodate reading is just one of the advanced tactics it uses to fulfill human needs that have outpaced its own evolution. Further changes are now being seen as humans grow up exposed to technology, screens, and the constant scrolling that has taken over a large portion of many people’s lives. The brain will continue to adapt, and the neurons firing in someone who grew up nowadays may be very different from those of an aging person born seventy years ago.
