Pinar Demirayak, Ph.D., and Kristina Visscher, Ph.D.Every brain is wired somewhat differently, but a new study led by Pinar Demirayak, Ph.D., a researcher in the lab of Kristina Visscher, Ph.D., associate professor in the Department of Neurobiology, suggests that the parts used most for demanding, attention-heavy tasks may become the most distinctly personal of all. The study, published in the Journal of Neuroscience, explores the broader idea that experience reshapes neural connections, making the brain's networks better suited to their lived environment.
Rewriting the rules of sight
Demirayak co-authored the paper, titled "Increased Attentive Use Is Linked to More Idiosyncratic Functional Connections," with Visscher, Leland Fleming, Ph.D., an assistant professor at Texas A&M University, and lab members Pauline Stewart and Rachel Chua. They found that the more attention a brain region gets, the more its connections to the rest of the brain become distinct across individuals, while regions used more passively look strikingly similar from person to person.
To test the idea, Demirayak and her colleagues took advantage of a unique property of the visual system: central vision (the sharp, detailed vision at the center of your gaze) and peripheral vision (everything outside that direct point of gaze) are processed by separate regions of the brain's primary visual cortex.
“We examined this in two contexts where different parts of primary visual cortex are used for more (or less) attention-demanding visual tasks,” said Demirayak. “We rely on the amazing fact that the visual cortex is retinotopically organized; that is, central vision is processed by different cortical regions than peripheral vision.”
People with healthy eyesight rely heavily on central vision, via the eye's fovea, for effortful visual tasks like reading a page or scanning a face and rarely use peripheral vision that way. But some people who lose their central vision, often due to macular degeneration, adapt by developing what's called a preferred retinal locus, or PRL: a patch of remaining peripheral retina that effectively becomes a substitute fovea.
Over time, that patch gets used the way central vision once was, for the demanding tasks of daily life, while the rest of a person's peripheral vision continues to be used the way it always was. To further explore this, Demirayak zeroed in on a well-understood feature of the visual system that allows them to compare heavily and lightly used brain regions side by side.
Fingerprints in the brain
Using brain scans from 23 people with healthy vision and 21 people with central vision loss, collected while they were resting quietly, Demirayak mapped how each region's whole-brain connectivity pattern compared to everyone else's. The results, in people with healthy vision, were clear. Parts of the brain that process peripheral vision looked almost the same from person to person, while parts of the brain that process central vision were highly individualized.
“We find that the whole-brain patterns of connections to the cortical representations of peripheral vision are quite similar person-to-person... ‘if you've seen one, you've seen them all,’” said Demirayak. “On the other hand, when you look at whole-brain patterns of connections to central representations, they are idiosyncratic, like people's fingerprints... ‘if you've seen one, you've seen only one.’”
One exception to the rule
The second half of the study looked at people who had lost central vision as adults. Their brains, overall, didn't rewire dramatically — with one striking exception, in exactly the spot that theory would predict.
“We find that whole-brain patterns of connections of the visual cortex don't change much for people with central vision loss,” said Demirayak. “Except, in the cortical representations of the preferred retinal locus, which people use preferentially for attention-demanding tasks.”
Because these patients developed vision loss later in life, the individualized pattern in their PRL couldn't be attributed to something laid down early in brain development. It appeared to be a product of the specific way each person came to use that patch of cortex.
“The cortical representation of the PRL shows much more idiosyncratic patterns of connections than a control region,” said Demirayak. “This suggests that the idiosyncratic connections are associated with experience, not development, since these patients developed vision loss in adulthood.”
A new lens on plasticity
Beyond the visual system findings, the study proposes a broader methodological shift in how scientists study brain plasticity. Rather than comparing the average brain pattern of one group to another — an approach that can wash out real but idiosyncratic changes — the researchers measured how far each individual's pattern strayed from the norm.
“We're excited about the finding, in part because it has opened our eyes to new ways of thinking about adult plasticity,” said Demirayak. “The field often examines neural plasticity by comparing the mean of one group to the mean of a control group.”
“That ignores the knowledge that each person's pattern of brain connections starts out distinct, and an experience is likely to perturb each system slightly differently,” said Demirayak. “By examining the idiosyncrasy of the connections, we can identify plasticity in connection patterns.”
Demirayak and other authors note the approach could eventually support more personalized rehabilitation strategies for people with vision loss, since a "one-size-fits-all" model may miss how differently each patient's brain has adapted. More broadly, they suggest the same idiosyncrasy-based method could be applied to other kinds of experience-driven brain change, from musicians' motor cortex to the brains of people who have lost limbs.
What emerges is a different picture of adult plasticity than the field has typically painted: not a dramatic rewiring, but a slow, personal recalibration. The next question is whether that same idiosyncratic imprint appears wherever attention lingers — not just in how one sees, but in how one hears, moves, and remembers.