Supporting Material Vol 1 - Colourful Language

Key Research
Do You See What I See? by Beau Lotto
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. Neuroscientist Beau Lotto explains.
Colour is one of our simplest sensations… even jellyfish
detect light 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 light can take on
any colour… in our mind.
Here’s another example. If you look at the cubes to the
right, 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 Memories
Colour is arguably our best creation, one that is created
according to our past experiences.
his is why you see optical illusions, because when
looking at an image that is consistent with your past
experience of “real life”, your brain behaves as if the
objects in the current images are also real in the same
way.
If we are using past experience to make sense of light,
how quickly can we learn to see light differently? It is a
matter of seconds. To demonstrate this we had a large
group of people for Horizon try an illusion.
First notice that the two desert scenes have exactly the
same colour composition. The skies are both blueish
and the deserts are both yellowish.
However, when you stare at the dot between the red
and green squares for 60 seconds, and then look back
at the dot between the two desert scenes, the colours
of the two identical scenes will astound you.
The more focused you are in staring at the dot between
the green and red squares the better the subsequent
illusion will be.
The desert scenes change colour because your brain
incorporated its recent history of redness on the left and
greenness on the right in the second image and applied
it to the desert scenes when you looked at them for the
second time … at least for a while.
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.