Do You See What I See?
Colour does not actually
exist... what exists is light
Roses are red, violets are blue - or are they? The
colours you see may not always be the same as the colours someone else sees… as
we see colour through our brains, not our eyes. Colour is one of our simplest
sensations… even jellyfish see lightness and they do not have a brain. And yet
to explain lightness, and colour more generally, is to explain how and why we
see what we do.
The first thing to remember is that colour does not
actually exist… at least not in any literal sense. Apples and fire engines are
not red, the sky and sea are not blue, and no person is objectively
"black" or "white". What exists is light. Light is real. You
can measure it, hold it and count it (well … sort-of). But colour is not light.
Colour is wholly manufactured by your brain. How do we know this? Because one wavelength of light can take on any colour… in our
mind.
Here's an example. If you look at the cubes at the
below, notice the four grey tiles on the top surface of the left cube and the
seven grey tiles on the equivalent surface of the right cube. Once you've
convinced yourself that these tiles are all physically the same colour (because
they are), look at the next image down. What's amazing
is that now the grey tiles on the left look blue, whereas the same grey tiles
on the right look yellow. The yellow and blue tiles of the two cubes share the
same light, and yet look very different.
Colour is arguably our best creation, one that is
created according to our past experiences. This is why you see optical
illusions, because when looking at an image that is consistent with your past
experience of "real life", you brain behaves as if the objects in the
current images are also real in the same way.
These two facts raise an intriguing possibility.
Maybe colour is more fundamental to our sense of self than we thought
previously. And indeed it is. Remember,
colour has been at the heart of evolution for millions of years. Think of the
relationship between insects and flowers (flowers are not coloured for our
benefit, but for theirs), or of all the different colours of animals and how
they either blend into their environment or, like the peacock, stand out in
order to attract attention. Think about the colours of the clothes you are
wearing… and why you are wearing them. The whole of the fashion, cosmetic and
the design industries are predicated on colour.
Perception-based evolution
What this means is that our simplest perception has
shaped who we are. What's more, and this is amazing
indeed, colour, which remember does not exist, has shaped the physical tapestry
of the world itself. It has also been at the heart of human culture.
It is because of our intimate relationship with
colour that people have been wondering for centuries, whether you see what I
see? The answer will tell us not only a great deal about how the brain works,
but also about who we are as individuals and as a society.
Colour perception means no matter what colour light
we look at bananas under they always look yellow. My lab created several unique
experiments for a group of 150 people of different ages, backgrounds, races and
sex. Our aim was to see if we all see colour the same. What we found really
surprised us (though note that our findings are just the beginning of the
answer).
In an experiment testing the relationship between
emotions and colour we discovered that nearly every adult assigned yellow to
happiness, blue to sadness and red to anger (surprise and fear, which are the
other two universal emotions, had no obvious colour). While children showed the
same trend, their choices were far more mixed and variable.
On the other hand nearly everyone (young and old)
showed a similar relationship between colour and sound, where lower notes are
thought to be best represented as dark blue and higher notes as bright yellow.
In other words people seem to have internal mental maps between colour and
other perceptual qualities, such as sound and form. Amazing
when these relationships do not exist in nature.
Colour structures
In another experiment we asked people to put 49
coloured blocks on a surface area of 49 spaces. They had no other instruction.
The number of possible images that could have been created was 10 raised to the
power of 62 - a huge number. What's remarkable that people made patterns that
were largely predictable, because everyone grouped colours together according
to similarity. Why? Because we have an inherent need for structure, and in
particular structures that are familiar, in this case structures that are
similar to the mathematics of the images of nature.
In yet another experiment that really looked at the
fundamentals of colour vision, we asked whether there might be individual
differences in simply detecting light. What we discovered is that not only are
women more sensitive than men, but also women who feel they have a stronger
sense of control are significantly better than those women who feel powerless.
Remarkable really when one remembers that we're just talking about light
detection.
We also examined whether colour can actually alter
our sense of a minute. Our initial observations suggested that a minute takes
longer for men than for women… about 11 seconds longer on average. But a minute
took longer for men and women when surrounded by red light, as compared to blue
light. This effect is likely to be linked to arousal since it is well-known
that red and blue create different states of arousal in men and women alike.
Deluded species?
So we all see the world differently. Indeed, we have
no choice about this because our experiences of the world are necessarily
different. None of us sees the world as it is. In this sense we are all
delusional, what each of us sees is a meaning derived from our shared and
individual histories.
This awareness, possibly more than anything else,
provides an irrefutable argument for celebrating diversity, rather than fear in
conformity. Which is liberating, since knowing this gives you
the freedom (and responsibility) to take ownership of your future perceptions
of yourself and others.
Article taken from the BBC’s Science and
Environment Page
8th August 2011