I had a strange dream last night.
Three blue cats jumped onto my bed.
I wasn’t at home but in a hotel at the top of the Himalayan mountains.
Bach’s Goldberg variations were playing in the background.
And then one of the cats bit my hand!
It all felt so real at the time.
Yet when I finally woke up I realised that the cats, the mountains, the music
had just been conjured up in my mind’s eye. None of it was real.
How had the neurons firing in my brain generated a sensation of blue cats?
If I look at the blue of the sky then I know that it’s blue because of the
specific wavelength of the light entering my eye.
And yet I’d generated that sensation of blue in my dream
without the need for any light at all. How does my brain give me the feeling of blue?
The sensation of blueness, the sound of the piano,
and the pain in my hand are all related
to what we call consciousness.
The thing responsible for the “I”
that experiences the world around me.
As Descartes declared: “I think therefore I am".
But what is this "I"?
Where is it?
The idea that the mind is separate from the brain is what Descartes called dualism.
And the duallists love to butt heads with the materialists,
the guys who say that there is only one kind of stuff – matter –
the stuff of quarks, thermodynamics, earthquakes, photosynthesis.
Modern brain imaging techniques are today's telescopes,
allowing us to look into the brain in action.
We might be able to identify a very specific
region that is active when I think about say... maths,
or running through a field of grass.
Or three blue cats.
That then turned red!
They can even predict some of my decisions a whole 6 seconds
before my consciousness becomes aware of them.
So can they tell us what makes a brain conscious?
Perhaps I need to go back to sleep to find out.
The brain is at its most unconscious in something called deep stage four sleep.
No dreams. No feelings. Nothing.
So can we find out what is different about
the way the brain works when it is awake?
Using transcranial magnetic stimulation
you can switch on neurons in the brain and see the effect.
In the awake brain information floods back and forth
across the network of synapses and neurons with an obvious feedback behaviour.
The unconscious sleeping brain sees none of these feedback loops.
This has led to a new mathematical formula called Phi
which attempts to measure the difference in the network behaviour of a conscious brain.
Does what it means to be “me” come down to a mathematical equation?
I like the idea of that!
But what about other networks?
Your gut has as many neurons as there are in the brain of those cats.
Could my gut be conscious?
Most of the neurons of an octopus are in its arms.
So what kind of experience does an octopus have?
A centralised one or many peripheral ones?
Could my phone ever identify itself in the mirror?
Declare “iPhone think therefore iPhone am." The internet has a few billion nodes.
Each node has hundreds of millions of transistors whose interconnectedness begins to approach
the interconnectedness of biological systems.
The intriguing thing is that we are all just
lots of electrons and quarks put together to make a human being.
The challenge is working out how many atoms you need
and how do you put them together in order to get consciousness.
Maybe there's a magic ingredient that you need to add
that we just haven’t discovered yet.
Or maybe we should think of consciousness in a totally different way.
More like an emergent phenomenon that can’t
be reduced to simple building blocks.
After all one molecule of H2O isn’t wet.
But put lots together and wetness emerges.