Marina Bedny
Department of Psychological and Brain Sciences
Johns Hopkins University
Built to learn: Insights into nature and nurture from blindness and cognitive expertise
What enables humans to develop a shared repertoire of rich conceptual representations and at the same time adapt to environments as diverse as the Arctic, the Amazonian rainforest and New York City? I will discuss insights into this puzzle from studies with people who are blind and one study with Python coders. The evidences touches on three related questions: 1. How does sensory experience contribute to conceptual and perceptual systems? 2. How cognitively flexible are cortical systems? 3. What is the role of domain specific vs. domain general cortical systems in learning?
The question of how sensory experience contributes to the mind and brain is central to many cognitive and neural theories. One way the British empiricists approached the problem is by conducting thought experiments on blindness. They concluded that ‘visual’ concepts, such as color, are fundamentally inaccessible to people born blind. Contrary to this idea, I will present evidence that blind and sighted people have ‘visual’ knowledge (e.g. of color and light) that is similarly inferentially rich and has a similar neural basis. Blindness illustrates that inferential learning and linguistic communication is sufficient to construct shared ‘visual’ knowledge from innate primitives in the absence of sensory evidence. In contrast to preserved conceptual systems, blindness dramatically reorganizes cortical systems that evolved for visual perception. In congenital, but not late, blindness ‘visual’ cortices participate in higher-cognitive functions, including language and symbolic math. This evidence suggests that human cortex is cognitively pluripotent early in life but leaves open the question of how we acquire critical cultural knowledge throughout the lifespan. One influential proposal is that lifelong cultural learning occurs by “recycling” domain specific cortical maps (e.g. recycling contour recognition for reading). I will present evidence from Python experts that highlights the importance of domain general(ish) mechanisms for cultural symbol systems. The human brain combines specialization and flexibility to enable unprecedented learning capabilities.
This seminar will be recorded.