When you think about the visual cortex—the part of the brain responsible for processing everything the eyes see—you likely imagine it as a single-purpose tool.
It’s the hub where colors, shapes, and motion come to life.
But what if this ancient structure could be repurposed for something completely different, like solving math problems?
Recent research reveals that for people who are blind from birth, the visual cortex takes on a surprising new role: crunching numbers.
This groundbreaking finding offers not only fresh insight into the brain’s adaptability but also challenges long-held beliefs about how our neural networks are wired.
What’s more, it provides a deeper understanding of how the brain’s inherent plasticity might unlock new possibilities for rehabilitation, learning, and beyond.
The Study That Challenged Assumptions
A team of researchers at Johns Hopkins University, led by Shipra Kanjlia, conducted a small yet intriguing study to explore how blind individuals process math problems.
They recruited 36 participants, including 17 who were blind from birth, and scanned their brains using functional magnetic resonance imaging (fMRI) as they performed mental arithmetic tasks.
To ensure fairness, the sighted participants wore blindfolds during the tests.
The results were eye-opening. Both blind and sighted participants displayed similar activity in a brain region called the intraparietal sulcus, known for its role in number processing.
This suggests that the ability to “visualize” numbers is not tied to actual visual experiences.
“The visual cortex is this ancient structure that’s always processed vision.t
You would think that could never change,” said Kanjlia in an interview with New Scientist. “But then you find it does.”
However, the most fascinating discovery lay elsewhere.
Among the blind participants, the visual cortex itself became active during arithmetic tasks—and its activity increased as the math problems grew harder.
This was not the case for the sighted participants.
A Pattern Interrupt
It’s easy to assume that the brain is a collection of rigid, specialized regions—each performing its assigned task.
The visual cortex processes sight. The auditory cortex handles sound. End of story, right?
Not quite. This study disrupts that assumption, suggesting instead that the brain is far more flexible than previously believed.
For blind individuals, the visual cortex appears to be “repurposed” for non-visual tasks like mathematics, thanks to the brain’s remarkable plasticity.
“The number network develops totally independently of visual experience,” Kanjlia explained in a press statement.
“These blind people have never seen anything in their lives, but they have the same number network as people who can see.”
The implications of this are profound. If the visual cortex can adapt to process numbers, what other untapped potential might it hold?
Neuroscientist Marina Bedny, a co-author of the study, summed it up best: “If we can make the visual cortex do math, in principle, we can make any part of the brain do anything.”
Not a New Phenomenon
This isn’t the first time scientists have observed the brains of blind individuals rewiring themselves to take on new tasks.
Back in 2010, a study conducted at Georgetown University Medical Center found that the visual cortex of blind individuals could also enhance other senses like touch and hearing.
For example, reading Braille or identifying objects through sound activated this typically sight-focused area of the brain.
Fast forward to 2022, and another Johns Hopkins University study discovered that blind children used their visual cortex to process speech.
According to researchers, it was as if the brain had “colonized” the visual cortex for a different purpose entirely.
Neuroscientist Rebecca Saxe commented at the time: “In some circumstances, patches of cortex appear to take on other roles than the ones that they most typically have.”
How Does the Brain Adapt?
The brain’s ability to repurpose itself stems from its incredible neuroplasticity—the capacity to rewire and adapt based on new experiences or the absence of certain stimuli.
For individuals who are blind from birth, the lack of visual input leaves the visual cortex “unoccupied.”
Rather than letting this prime real estate go to waste, the brain assigns it to tasks like math, speech, or sensory enhancement.
In the case of math processing, the researchers believe the visual cortex is being recruited because of its computational capabilities.
Processing visual information requires analyzing complex patterns, spatial relationships, and detailed structures—skills that are surprisingly transferable to solving mathematical problems.
What Does This Mean for Science and Medicine?
The discovery that the brain can repurpose the visual cortex for math and other tasks opens up exciting possibilities in several fields:
- Rehabilitation and Therapy: For individuals with brain injuries or sensory impairments, harnessing the brain’s plasticity could lead to new methods for restoring lost functions. Imagine training the visual cortex to compensate for damage in other parts of the brain.
- Education and Learning: Understanding how the brain adapts could inform new teaching strategies, particularly for children with disabilities. Tailored learning methods might leverage the brain’s ability to rewire itself.
- Artificial Intelligence and Neural Networks: Insights from brain plasticity could inspire advancements in AI, particularly in creating systems that mimic the brain’s adaptability.
- Cognitive Enhancement: Could we one day train our brains to repurpose underutilized regions for entirely new skills? The possibilities are tantalizing.
Unanswered Questions
While this study sheds light on the brain’s adaptability, it raises just as many questions. For instance:
- Are there limits to how much the visual cortex (or any other brain region) can be repurposed?
- Does this rewiring come at a cost, such as reduced performance in other tasks?
- How does the timing of sensory deprivation—such as being blind from birth versus losing sight later in life—affect the brain’s ability to adapt?
Future research will undoubtedly delve deeper into these mysteries, offering even more insight into the brain’s untapped potential.
The Takeaway
The brain’s ability to rewire itself is nothing short of astonishing.
For individuals who are blind, the visual cortex—once thought to be solely dedicated to sight—becomes a versatile tool, capable of processing numbers, speech, and even enhancing other senses.
These findings challenge long-held assumptions about the brain’s rigidity and open the door to a world of possibilities in neuroscience, education, and medicine.
As Marina Bedny aptly put it: “If we can make the visual cortex do math, in principle, we can make any part of the brain do anything.”
In a world where limitations are often taken for granted, the adaptability of the human brain reminds us of our extraordinary potential.
The question now is not just what the brain can do, but how we can harness its remarkable flexibility to improve lives.
