Think about the concepts of “red” and “justice” and you’ll notice a key difference. If you’re sighted, you’ll associate “red” most strongly with the sensory experience, which relates to signals from cone cells in your eyes. “Justice”, in contrast, doesn’t have any associated sensory qualities – as an abstract concept, you’ll think about its meaning, which you learnt via language, understanding it to be related to other abstract concepts like “fairness” or “accountability”, perhaps. But what about blind people – how do they think about “red”?
A brain-imaging study of 12 people who had been blind from birth, and 14 sighted people, published recently in Nature Communications, shows that while for sighted people, sensory and abstract concepts like “red” and “justice” are represented in different brain regions, for blind people, they’re represented in the same “abstract concept” region. Continue reading →