Sign Language Experience Reshapes Visual Cortex Organization in Deaf and Hearing Signers
A new fMRI study shows that learning sign language — especially during childhood — alters the organization of high-level visual cortex in the brain. Deaf signers showed the most pronounced changes, while hearing adults who learned sign language later also displayed measurable differences. The findings challenge long-held assumptions that the location of visual processing regions in the brain is largely fixed.
Researchers using functional magnetic resonance imaging found that high-level visual cortex develops a distinct topography in Deaf individuals who use sign language, reflecting the sustained visual and linguistic significance of hands throughout their development. In typical development, brain regions that process less-relevant visual categories — such as hands — are often repurposed over time, a process known as cortical recycling. However, when hands remain central to communication, as in sign language, this recycling appears to be redirected or suppressed. Hearing adults who acquired sign language later in life also showed significant, though less dramatic, changes compared to non-signers, suggesting that the brain retains some plasticity beyond the childhood sensitive period. The study proposes a revised framework for understanding human visual cortex, in which the functional geography of these regions is more malleable than previously believed. Sociolinguistic experience — not just early sensory deprivation — appears to be a meaningful driver of cortical organization.
What's missing
As a preprint, the findings have not yet undergone formal peer review.
What different sources said
- bioRxivCenter
Deafness and sign language experience shift visual category representations
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