Our brains don’t start out wired for reading. We’re not born with the ability to read. To learn to read, we have to use parts of the brain that evolved to do other things.
People with dyslexia have trouble with this. Certain reading instruction can lead to big changes, though. And technology allows us to see those changes.
See how learning to read changes the brain.
How learning to read changes the brain
Our brains aren’t pre-wired to translate letters into sounds. We learn to read by repurposing parts of the brain meant to do other things — visual processing, language comprehension, and speech production.
Researchers have studied these areas using a type of brain imaging called functional MRI (fMRI).
The temporo-parietal cortex and inferior frontal cortex play key roles in phonological processing. These areas help us sound out the words we’re looking at. The occipito-temporal cortex helps us recognize words by sight. As we recognize more words by sight, we can read faster.
These three areas are involved in reading no matter which language people read in. And differences in these areas are found in the brains of people with dyslexia all around the world.
How the brain works differently in people with dyslexia
The parts of the brain involved in reading don’t function the same way in people with dyslexia as they do in others. Some areas are less active, which is shown by the dashed lines below.
As reading skills improve with intensive instruction, brain activity increases in key areas in the left side of the brain.
Intensive reading instruction also leads to changes in the right side of the brain. The changes in the right side of the brain may help make up for weaknesses on the left. We need more research to figure out if all of these changes, on the left and right sides of the brain, need to happen for reading skills to improve.
What we still don’t know about reading and dyslexia
Researchers have been using a variety of tools to boost our understanding of reading and the brain. But there are still lots of questions. Scientists are working to figure out which brain differences cause dyslexia — and which ones are caused by it.
Brain anatomy: Researchers aren’t sure why the parts of the brain shown above are different in people with dyslexia. But their brain anatomy changes when they get intensive reading instruction.
Their brains create more gray matter and white matter. Gray matter contains the parts of brain cells (neurons) that communicate with each other. (They do this by sending electrical signals across a tiny space called a synapse.) White matter connects the gray matter in different parts of the brain.
Brain chemistry: People with higher levels of certain neurotransmitters are more likely to struggle with reading. These levels may make it harder for brain cells to send electrical signals. But it’s too soon to know if medication could help.
Brain waves: When groups of brain cells sync up their firing patterns, this electrical activity is called a brain wave. Different rhythmic patterns might affect the way people with dyslexia process sounds or letters.
It’s important to note that brain imaging is still only a research tool. Researchers don’t rely on brain scans to diagnose dyslexia.
Beware of “brain training” programs that advertise brain changes. They aren’t backed up by evidence that they improve reading skills. Reading instruction is key. Studies show that working on phonological awareness helps kids with dyslexia become better readers.
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About the author
About the author
Guinevere Eden, PhD is a professor at Georgetown University and director of its Center for the Study of Learning.