People born blind have never seen that bananas are yellow however Johns Hopkins University researchers find that like several sighted people, they perceive two bananas are more likely to be the identical color and why. Questioning the assumption that dates again to philosopher John Locke that people born blind could never actually understand color, the team of cognitive neuroscientists demonstrated that congenitally blind and sighted individuals really perceive it quite similarly.
“A common instinct dating back to Locke is that a blind person could learn the arbitrary fact that marigolds are ‘yellow’ and tomatoes are ‘red’ but would nonetheless miss out on the in-depth understanding of color,” said senior author Marina Bedny. “The idea is that to actually know one thing it’s important to see it for yourself, and without vision, you choose up shallow facts by talking to people. This study with blind people suggests the opposite. Talking to people conveys in-depth understanding of color better than arbitrary color facts.”
The findings are published in Proceedings of the National Academy of Sciences.
In a two-phase experiment, blind and sighted adults have first requested the widespread color of objects (the arbitrary facts), why they were that color, and the probability that two of these objects selected at random could have the same color. The objects were a mix of natural things (fruits, plants, gems) and man-made ones (pen, dollar bill, stop sign).
Although blind individuals didn’t always agree with sighted people about arbitrary color facts, say, that bananas were yellow, blind people’s reasoning about why bananas are yellow and judgments about how seemingly two bananas are to be the identical color (color consistency) were similar to sighted people, the team found. The outcome held throughout several types of objects, together with these which can be colored for specific reasons, like cease indicators, cash, and even wedding dresses.
Blind and sighted individuals additionally displayed the identical depth of understanding in explaining why objects had certain colors, said lead author Judy Kim, a former Johns Hopkins graduate student who’s now a postdoctoral associate at Yale University.
The color of polar bears was one revealing example from the experiment. All sighted participants said they’re white to blend in with the snow, however, some blind participants said they’re black to soak up warmth and keep heat. “Blind people give a coherent rationalization of a polar bear’s color even after they don’t agree with sighted people on the actual color of a polar bear,” Kim said.
Subsequently, the team requested participants to make predictions in regards to the colors of imaginary objects they’d by no means seen or heard of in an “explorer on an island” scenario. “We wanted to see how people reason about issues they’ve by no means experienced,” Kim said. “It’s an effective way to test the depth of people’s color understanding.”
The team informed participants about items found on a distant island the place the people have their very own language, tools, machines, customs, and many others., and the island ecology is unique. Participants heard about objects like “a green gem that’s spiky the size of a hand” and “a gadget that’s triangular, yellow, and the size of a thumb,” after which requested how seemingly one other a type of would even be the same color.
Blind and sighted people made identical judgments about these novel objects, exhibiting that their color knowledge generalizes to new examples and isn’t depending on memorizing.
In an associated recent study, the team similarly found that whereas blind individuals haven’t seen an animal like elephants and lions, they make knowledgeable guesses about their look primarily based on an understanding of why animals look the way in which they do (e.g., mammals that reside on land have legs).
Bedny would next like to find out how color data is managed in the brain and to work with blind children to attempt to find out how and when blind and sighted people purchase understanding of color.
“We hypothesize it’s by informal studying by way of dialog and reading, however, when precisely does that occur?” she said. “Do blind and sighted children learn this information in an identical manner? Are there developmental variations where sighted children acquire the information at an earlier age, earlier than they’re utilizing language and blind children acquire it only after they learned to speak after which catch up?”