ByJill Rosen
/ Published
Aug 17, 2021
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- Jill Rosen
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- 443-997-9906
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People born blind have never seen that bananas are yellow, but Johns Hopkins University researchers have found that like any sighted person, those born blind understand two bananas are likely to be the same color and why. Questioning the belief that dates back to philosopher John Locke that people born blind could never truly understand color, the team of cognitive neuroscientists demonstrated that congenitally blind and sighted individuals actually understand it quite similarly.
"A common intuition dating back to Locke is that a blind person could learn the arbitrary fact that marigolds are 'yellow' and tomatoes are 'red' but would still miss out on in-depth understanding of color," said senior author Marina Bedny. "The idea is that to really know something you have to see it for yourself, and without vision, you pick 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 were first asked the common color of objects (the arbitrary facts), why they were that color, and the likelihood that two of those objects selected at random would be the same color. The objects were a combination of natural things (fruits, plants, gems) and man-made ones (pen, dollar bill, stop sign).
Even though blind participants 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 likely two bananas are to be the same color (color consistency) were identical to sighted people, the team found. The result held across different types of objects, including those that are colored for specific reasons, like stop signs, coins, and even wedding dresses.
"The idea is that to really know something you have to see it for yourself, and without vision, you pick up shallow facts by talking to people. This study with blind people suggests the opposite."
Marina Bedny
Blind and sighted individuals also displayed the same depth of understanding in explaining why objects had certain colors, said lead author Judy Kim, a former Johns Hopkins graduate student who is 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 but quite a few blind participants said they're black to absorb heat and stay warm. "Blind individuals give a coherent explanation of a polar bear's color even when they don't agree with sighted people on the particular color of a polar bear," Kim said.
Next the team asked participants to make predictions about the colors of imaginary objects they'd never seen or heard of in a "explorer on an island" scenario. "We wanted to see how people reason about things they have never experienced," Kim said. "It's a great way to test the depth of people's color understanding."
The team told participants about items found on a remote island where the people have their own language, tools, machines, customs, etc., and the island ecology is unique. Participants heard about objects like "a green gem that is spiky, the size of a hand" and "a gadget that is triangular, yellow, and the size of a thumb," and then asked how likely another one of those would also be the same color.
Blind and sighted people made identical judgements about these novel objects, showing that their color knowledge generalizes to new examples and is not dependent on memorizing.
In a related recent study, the team similarly found that while blind people have not seen animal like elephants and lions, they make informed guesses about their appearance based on an understanding why animals look the way they do (e.g., mammals that live on land have legs).
Bedny would next like to determine how color knowledge is managed in the brain, and to work with blind children to try to learn how and when blind and sighted people acquire understanding of color.
"We hypothesize it's by casual learning through conversation and reading but when exactly does that happen?" she said. "Do blind and sighted children learn this information in the same way? Are there developmental differences where sighted children acquire the information at an earlier age, before they're using language and blind children acquire it only after they learned to talk and then catch up?"
Authors include former Johns Hopkins research assistant Brianna Aheimer, and Verónica Montané Manrara, a former Johns Hopkins student now in a graduate program at Northwestern University.
Posted in Science+Technology
Tagged cognitive science, psychological and brain science
FAQs
Questioning the belief that dates back to philosopher John Locke that people born blind could never truly understand color, the team of cognitive neuroscientists demonstrated that congenitally blind and sighted individuals actually understand it quite similarly.
Can blind people understand colors? ›
Blind and sighted adults also share knowledge of similarities between colors (e.g., "green" and "blue" are similar but different from "orange" and "red"), although this knowledge is more variable among blind individuals (31–33).
Can blind people understand seeing? ›
While blind people cannot see as those with sight do, they can still perceive visual stimuli. They may simply do this differently. For example, people with low vision may use the following tools to see more accurately: large or bold text.
Is it possible for those who have always been blind to understand colors? ›
Though blind people lack the sensory experience of colour, they can nonetheless – thanks to language – form rich and accurate colour concepts, Caramazza notes.
How do you explain colour to a blind person? ›
Attach Emotions and Feelings to Color.
Help your child understand color by relating it to her other senses. You might describe red as a hot, loud color; white as smooth and quiet; black as shiny; or blue as the notes of a saxophone. A blind blogger once wrote: Yellow is buttery and rich, like sunshine on your face.
Does everyone see color the same way? ›
Color perception is an exception. Women and men generally perceive colors differently. Women experience the world in warmer colors, for example, and can usually distinguish different shades of red better than men. Men, on the other hand, are better able to perceive poor contrast and rapid movement.
Do color blind people think differently? ›
This is not that strange, to the colorblind the name of a color is often irrelevant. They think in groups; blue/green/grey, orange/red/brown, black/green/grey. Naming a color is a frustrating process, prone to mistake. Something can without a doubt be green, but most of the time you really can't be sure.
Do people born blind dream? ›
While people who have been blind since birth do indeed dream in visual images, they do it less often and less intensely than sighted people. Instead, they dream more often and more intensely in sounds, smells, and touch sensations.
What do blind people see in a dream? ›
A dreaming blind person experiences more sensations of sound, touch, taste, and smell than sighted people do. Blind people are also more likely to have certain types of dreams than sighted people. For example, blind people seem to experience more dreams about movement or travel. View Source and more nightmares.
Can a blind person hear? ›
People with absent or impaired vision use acoustic impressions much more, which is why their sense of hearing is better trained - blind people hear better. They perceive sounds and especially changes better, for example traffic noise under a bridge or near a wall of a house.
Achromatopsia is also known as “complete color blindness” and is the only type that fully lives up to the term “color blind”. It is extremely rare, however, those who have achromatopsia only see the world in shades of grey, black and white.
Can blindness be cured? ›
There's no current cure for blindness. But treatments can offer help for some people, depending on the cause and progression of their vision loss. New treatments in various phases of development also offer hope, including gene and stem cell therapies.
What is the rarest form of color blindness? ›
Tritanomaly is the rarest of all color blindness conditions, affecting well under 0.01% of both males and females. People who experience Tritanopia are lacking in blue cone cells. Blue appears identical to green and yellow is easily mixed up with violet or even dark grey.
What is color blindness for dummies? ›
Color blindness occurs when you are unable to see colors in a normal way. It is also known as color deficiency. Color blindness often happens when someone cannot distinguish between certain colors. This usually happens between greens and reds, and occasionally blues.
How do you describe pink to a blind person? ›
Yes, colour blind people see the pink colour but they say it as light red. The light green colour and olive colour is also presumed pink colour by the colour blind people.
Do blind people know what red is? ›
“You could be talking to a blind person, and if you didn't know they were blind, you would never suspect that their experience of red is different from yours, because in fact they do know what red means. They know what it means in the same way you come to know what justice means.”
How do blind people know when to stop wiping? ›
Originally Answered: How do blind people know when they have finished wiping their bum? Blind people can feel whether or not they are clean after wiping themselves enough times. Most people have the ability to so the same thing. I myself have been wiping without looking for years, and I do not have a visual impairment.
Do blind people have synesthesia? ›
Here, we provide evidence that, despite the aforementioned results and hypotheses, synesthesia can develop in the complete absence of vision by reporting, for the first time to our knowledge, the case of a congenitally blind person (CB) with graphene–texture, lexeme–texture and spatial sequence synesthesia.
Can colorblind people see things we can t? ›
The colorblind don't see the world in black and white, they can see color, but they a narrowed color perception. Colors lie closer to each other and are not as vibrant or bright as someone who isn't color blind would see it.
