Michael Arcaro, Ph.D.

• Assistant Professor
• Department of Psychology
• University of Pennsylvania

Topographic scaffolds shape visual development

How does the brain develop areas specialized for distinct visual domains, and why do they emerge in consistent cortical locations across individuals? I argue that these specializations arise from visual experience acting on intrinsic topographic architecture. Face-selective regions exemplify this principle: they require visual input to develop yet emerge within retinotopic hierarchies established early in life. I will present simulations demonstrating that such topographic organization can arise from self-organizing processes spreading from primary visual cortex. This account is incomplete, however, as expansion of human visual cortex relative to macaques would predict more areas from local wiring mechanisms, but our comparative studies instead reveal larger ones, pointing to additional developmental constraints. I will present evidence from neonatal diffusion tractography showing that subcortical structures, particularly the pulvinar, provide such constraints through thalamocortical pathways present at birth that may guide the spatial organization of specialized cortical domains. Finally, I will discuss how these cortical and subcortical topographic scaffolds continue to shape visual processing throughout adulthood. Together, these findings suggest that topographic organization provides a fundamental architectural principle linking neural development, structural connectivity, and functional specialization.

Faculty Host: Dr. Kristina Nielsen