*Special Time* Hybrid Colloquium: Brain plasticity in people born blind: Individual differences of plasticity and sight restoration

Abstract: 
What does the visual cortex do in people born completely blind? Early-onset blindness leads to reorganization in visual cortex connectivity and function, but this reorganization is not random. I will present evidence that plasticity plays different roles in early as compared to association visual cortex regions. Specifically, the association visual cortices maintain some of their original roles, processing information for categories parallel to those they process through vision (e.g. script and body shapes). In contrast, the early blind visual cortex is recruited for many non-visual tasks across sensory modalities (audition, touch, smell) and cognitive domains (perception, action, memory, language). This has led to theoretical disagreement about the role the visual cortex in blindness, and more broadly, about the capacity of the human brain for plasticity. However, research of brain plasticity has mostly been conducted at the group level, largely ignoring differences in brain reorganization across early blind individuals. I will present findings in a large cohort of blind individuals that shows that reorganization of early visual cortex is not ubiquitous, offering a solution to the diversity of group-level findings. It additionally highlights the important role for sensory experience during development in driving individual differences. Building on these findings, I will discuss how variability in reorganization in the early blind may affect the capacity to benefit from sight-restoring treatment. Overall, our data highlight the diversity in brain plasticity across regions and people, and the potential of harnessing individual differences for fitting rehabilitation approaches for vision loss. https://neuro.georgetown.edu/directory/striem-amit/