Seeing the world through rose coloured glasses?

[Fantazmic]

colour blindness testing is what tells us how people see different colours.
My hubby for example is red green colour blind and occasionally with certain colours he will see them differently to me. He'll say no its too green when I know it isnt green at all for example. When we do the colour blindness tests you can tell he is seeing colours differently. it is quite an accurate way of testing who sees what and how

 

[kawasakirider]

But it only tests for red/green colour blindness. My brother has this, too. It still doesn't mean we all see colours the same way.

 

[Renenet]

KR, I think about these things a lot. I could never immerse myself in philosophy as a career, but it's nice to massage the "what if", "how" and "why" part of the brain.

I won't write a long version because I have to get back to work, but some random thoughts:

- I've sometimes had disagreements with people over what colour something is, usually with a shade that doesn't fit neatly into a universally accepted colour category. This suggests that although there are colours that most can agree on, there are subtle differences in perception.
- Sensory perception is different in people with autism, who often have, for example, very sensitive hearing or an abhorrence of bright light. I'm not sure if the sensitivities extend to colour - I've tried to Google it but it's surprisingly hard to find information - but it wouldn't surprise me.
- Synaesthesia is a condition where senses are connected. It can be any of the senses, not just colour, but I'll use colour examples here. Some people see colour when they listen to music, others might associate letters and numbers with certain colours. Without the help of drugs.
- Synaesthesia is a neurological condition and in large part, so is autism. Therefore neurology plays a part in our perceptions.

I could probably go on but I need to get some work done!

 

[junglepython2]

But it only tests for red/green colour blindness. My brother has this, too. It still doesn't mean we all see colours the same way.

There are other tests for blue colour disorders, but you are right most testing is for blue and green defects as they are by far the most common.

 

[KaotikJezta]

its a matter of nature and nurture in the case of taste perception, nature as in some things we are inclined to prefer such as sweets (sugars) and fats, as they both help our predecessors survive and,well, do stuff.

kids have been shown to be more sensitive to taste, just because they tend to be more vulnerable to anything perceived to be toxic or dangerous (usually that comes in the form of bitterness)

supertasters have denser papilla and are more sensitive to flavours, a little can really go a long way for them

nurture wise, it's the things that you grow up with. Personally i absolutely hate vegemite, while i'd happily chow down on a durian, something most westerners would relate to having the smell of onions, sweaty gym socks and death with the texture of curdled milk. I just think of it as natural custard... mmmm....tasty

back on colour, i do believe there is a certain degree of opinion in stating the identity of something, example, one time a friend had these jeans which she said was really dark green... Well i thought it was just black, so we made a bet and asked one of the tutors to guess. She said black, but then again, what was the colour of those jeans? Perhaps there wasn't enough light reflected back? (cones need a certain amount of light to activate, rods on the other hand do fine in the dark) Perhaps one of us didn't recognize the colour spectrum as being one or the other? Too many variables to make a decision me thinks.

Well, as there are only a few ways to make black dye she was probably right. Black is usually very very dark green or very very dark blue when it comes to fabric dye.

 

[Bluetongue1]

Is a red rose in a completely dark room still red?

Have look at your TV screen, close up until you can see the individual pixels. What do you notice?

The basic philosophical question is: “Do sensory qualities such as sounds, smells or colours exist in objective reality rather than the mind of the perceiver.”

I think you need to firstly distinguish between sensory input and sensory perception. Secondly, as has been pointed out, perception can be influenced by learning, experience and expectations. Sensory input is the physical stimulation of receptor neurones resulting in nerve impulses being sent to the brain. Sensory perception is the interpretation and organisation of that information, such that we make sense of the world around us.

Here’s another way to look at the question which you may find useful. This is a thought experiment. Imagine you raise someone in a bubble with no light on them. Then, as an adult you place them in a room where each wall is painted red on one half and blue on the other. Would they see the two colours?

The structure of our sensory organs is the same for all humans. However, there can size and other differences which influence their gross functioning. The actual receptor cells are identical with some minor variations. Taste and smell involve the receptor’s ability to take in specific molecules at given sites within the receptor and then fire of a nerve message (a process called transduction). Some people lack the ability to transduce certain molecules (genetically determined) and therefore are unable to taste or smell these.

The rainbow consists of Red, Orange, Yellow, Green, Blue, Indigo and Violet. Where then do colours like Pink and Brown come from and how come we can see them?

The visible light spectrum is a continuum. While we can readily distinguish pure red from pure orange, it is not so easy to identity at which point on the spectrum one changes into the other. Aqua would be another example = blue or green? Therefore decisions at all the changes of colour are subjective.

Putting a name to colours involves more than sensory perception. It involves learning and recognition. Given the rage of colours available, the variety of names given them etc schools never teach more than the primary colours.



A few extra notes…

We think of the colour of an object being due to light bouncing off it. If that were the case, the object would tend to shimmer as it is moved. Some fabrics do have this effect. Most absorb all the incoming light and then re-emit it at a particular wavelength.
Plants absorb and use the blue and red ends of the spectrum for photosynthesis. This is due to the presence of Chlorophyll, which re-emits light in the green wavelengths – why plants are green. A green light on a plant will make it look good but will eventually kill it.

Humans have three different receptor cells for colour vision. These are called cones and only operate in bright light. In dim light, we have a different receptor cell that operates, called a rod, which reacts to all different wavelengths of visible light i.e. black and white vision. FYI – only cones are found in the central part of the retina and rods are found outside that area. So if you are trying a find a key hole in dim light and look directly at, it disappears. If you look to one side, you can see it in your peripheral vision.

Blue

 

[spida_0000]

I had never actually thought about it... Until NOW!! lol

 

[nagini-baby]

i have been trying to explain this to people since i was little. im female and i have a rare genetic form of colour blindness. i see shades but not exact colours. once i no what a colour is or what that shade of colour is i can usually pick up on it if i see it again. but the colours i see are probably not the colours that you see. so when you ask me to explain what i see. i cant.

 

[myusername]

kawasakirider, I used to bug my parents with this same question when I was a child. Glad to know there are people out there whose brains work as strangely as mine does.

 

[jack]

Just because a scientist says so, doesn't mean it's gospel.

cannot know what other eyes see, but i perceive this as gold... ahhh, philosphy

 

[kawasakirider]

Thanks for the input everyone, I didn't realise this thread had replies until just now.

Myusername, lol yeah I don't necessarily think we think strangely, just more in depth than others care to. Sometimes it bugs me that I think like this, rather than taking life as it comes, without question, but I think it's important to question things, especially things we don't understand.

Just out of curiosity, how did your parents answer you when you asked them this question when you were young?

cannot know what other eyes see, but i perceive this as gold... ahhh, philosphy

Science is different from religion because it is disprovable. Nothing is definite, which is what I said it's not necessarily gospel. Mock what I said all you like, but you cannot argue with that statement.

Nothing in science is absolute.

 

[Black.Rabbit]

The question has been bugging me for 15 years.

I didn't read the whole thread because I'm on my way to the land of nod (hopefully), so unsure if this has been suggested, but I think really the only way to tell is perhaps in eye transplants.

person recovers:
"oi, is this green?"
..."dude, no, that's purple man"

(then again... it could have too much to do with the brain, I'm not an ophthalmologist, so I am unsure of this).


One of my close mates is colour blind. Today at uni gives a perfect example, the lecturer gave out notes on yellow paper, she can't see yellow, instead she just saw dark brown paper with no words. When she drives at night she has to wear rose coloured glasses (funnily enough), otherwise she wouldn't see any road signs. She also can't see any fluro colours... they are all just a muggy brown to her. So we both turn our nose up in disgust when someone shows up to uni in fluro pink leggings and a fluro green singlet.

 

[Bluetongue1]

Visual Perception
The physiology of vision is anything but simple. I am not professing to understand it but I can give an overview. You have two basic parts. The first is sensory input with resultant firing off of fibres in the optic nerve. The second is the processing of this information in the visual cortex of the brain = visual perception.

The brain has been determined to increase the contrast between objects of similar hue and does so on a regular basis to help us interpret more readily what we are seeing. We also know that visual perception is dependent on such things as experience, memory and expectations. Clearly, different individuals will perceive the same thing differently, including colours.

Here’s an example to consider. Imagine you went to live in the rainforests of Brazil with a tribe that has had no contact with the outside world. When you look around at the forest surrounding you, all you perceive is a sea of different shades of green. Yet a tribesman can point out a lizard on a branch, a frog on leaf, a bird collecting nectar from a flower etc. Why do you have to struggle to see these when to the tribesman they are so obvious? You both have the power of vision (visual acuity) but your perceptions of what you see are very different. Over time you could learn to see as the tribesman does, with your visual cortex enhancing small colour differences to make such objects clear.

I hope this helps those who have pondered the question to answer it.


Colour defects
Each of our three types of cone cells contains a pigment (coloured chemical) which can absorb a certain range of light wavelengths (colours). If you map the amount of radiation (light) absorbed against the actual wave length, you get a bell-shaped curve. This is called the ‘absorption spectrum’ for that pigment. (Many, if not most absorption spectra are not smooth and bell-shaped, often having more than one peak).

The genes referred to earlier contain the information for producing each pigment. The common mutation for producing red pigment in the L cone produces a slightly different pigment with a slightly different absorption spectra. Consequently, it functions the same as the normal pigment in some wavelengths but differently in some others.

By the way, they have already developed a bionic ‘eye’ that hooks up a ”camera” to the optic nerve, for those who have been totally blind.

Blue

 

[Elapidae1]

My wife says my brown shorts are green. I don't wear them anymore.

 

[jack]

Mock what I said all you like, but you cannot argue with that statement.

if you are unable to see the wit, then we could no doubt argue black & blue.
i bring you the "good news", a Beryllium atom has an absolute number of 4 p+ in its nucleus.

 

[eipper]

Interesting thread......

Snakes don't sense heat with their tongues like they do with labial pits.

The eyesight of a snake is believed to be quite poor in many species (this is based from the size and shape of rods and cones and the amount of receptors), where in others it is thought to be quite similar to that of mammals. There are significant differences in the vision of mammals (eg Cats and a Platypus) so why is it assumed that there would not significant differences among reptiles????

One aspect/problem with comparing reptile physiology vs. Humans is the change correlation between body temps/metabolism. At cooler temperatures reptiles function at a slower rate, this affects different parts of the reptile body in different ways, eg from brain to muscle function and from external stimuli to the brain. So a reptile with a sub PBT may not react the same, as the same reptile at its PBT to the same stimulus.

One additional point re snakes vision (is while they are predators) they are unusual that most species to not have true binocular vision, which is extremely important to the perception of distance. And yet is you look at the orientation of the heat receptors (Labial Pits) along the front and sides of a snake they are angled towards the front. From this it would be reasonable to assume that they have a version of binocular heat perception. Much like the ears of owls and some microbats that have a similar version binocular (would this be Binauditary?) hearing.

Cheers,
Scott

 

[Bluetongue1]

My wife says my brown shorts are green. I don't wear them anymore.

So does mine - she can spot a grass stain at 50 paces and there goes my most comfortable work shorts into the wash again!



Science & Philosophy
There are some absolutes in science – gravity, charge law, force (4 basic forces in the universe), speed of light in a vacuum, matter etc. I do understand what you are saying about the nature of science. No matter how well we may have explained something, we should never close our minds to the possibility of change. Bear in mind though that vigorous testing / assessment must take place before we relinquish our current understanding for something new.

Basically, as a science person, my concern about a statement such as “Nothing in science is absolute” is that it is selling it short, as a wishy washy, change it at will pursuit. True science is robust. A lot of correctly obtained empirical data has to be gathered before changes can even be considered. Unfortunately, there is a lot of pseudoscience out there as well, masquerading as the real thing and giving the genuine scientists a bad name.

Science actually grew out of philosophy. The earliest scientists were philosophers. If you think about it, both pursuits have a lot in common. Science seeks to understand and explain the nature of the world around us and beyond. Philosophy seeks to understand such things as the nature of reality and existence. Each uses a somewhat different tool set – science uses empirical evidence while philosophy makes use of reason and logic.

Blue

 

[kawasakirider]

if you are unable to see the wit, then we could no doubt argue black & blue.
i bring you the "good news", a Beryllium atom has an absolute number of 4 p+ in its nucleus.

I had a chuckle when I read it, 'twas witty. I am not a fan of chemistry, but good job

 

[SYNeR]

We don't. Goes back to basic epistemology and subjectivity - a priori and a posteriori knowledge.

Ever heard of synesthesia?

Perhaps check out Immanuel Kant's transcendental arguments. A Critique of Pure Reason is a good starting point..

 

[Scleropages]

When you jump into others minds and see what they see it always looks different , so yes we all seem to see colors differently.
Solved.

Now can someone help me with random number gererators anmd how some people know what they will generate before an "event".

cHEERS bIG EARS!!!