Human brains are very complex, but why should any of it give rise to any kind of conscious experience whatsoever? What is the relationship between mind and matter? What is consciousness? How consciousness affects our personal and professional life.
Brain organoids are small blobs of neural tissue. They grow in the lab that resembles a certain feature of the human brain.
Nobody quite knows where consciousness comes from. But it is thought to be an emergent property that comes from neurons. Indeed it connect in a very complex but very specific way.
I like to think of consciousness science as a kind of jigsaw puzzle. We can look inside the human brains of other animals.
These are all different pieces. As we start to assemble the jigsaw, the picture is still not quite there yet.
So having new pieces is a great benefit. And the study of brain organoids provides us with one more piece of the puzzle.
To make brain organoids, we start with what are called pluripotent stem cells. Which are stem cells that can give rise to any cell of the human body?
And we just give them a nudge towards brain tissue. And then provide them with a three-dimensional environment that is very similar to the actual embryo.
Then the organoids essentially just grow themselves. So, if we look at the neurons within brain organoids, we can see electrical activity.
We can see whole large populations of neurons all firing at the same time. organoids provide a unique testing ground for theories of consciousness.
We can organdies as biological models of brain structure that we think may be important for consciousness.
Just as we use computational models to simulate how the brain might work in different ways? We can use organoids to not just simulate, but build system might exhibit different kinds of neural dynamics that we associate with consciousness.
It is unlikely that brain organdies are going to become conscious anytime soon.
For that to happen we would need many more neurons, and at the moment the different brain regions are just not organized properly relative to one another.
It is a bit like if you took an airplane and took all the pieces apart and put them back together a bit jumbled.
Each of the pieces of the airplane is there but that airplane would never fly. And the same is true, so this brain organoid cannot undergo any of that kind of high order thinking.
Are brain organoids conscious? One thing we know for sure about consciousness is that it depends intimately on the brain.
But of the human brain, every brain inside every human inside every animal is always part of a body is sensing and interacting with an environment.
Could a brain that is not part of a body that is not interacting with an environment at all, support conscious experiences?
If I am trying to figure out whether a fellow human being is conscious, I will tend to ask them you cannot ask an organic you start to have fixed points.
This means we need a measure of consciousness that does not depend on behavior that can infer the presence or absence of consciousness simply by looking at properties of the brain.
What makes the problem of measurement a bit easier in humans is that we have benchmarks. And once you start to have fixed points, then you can start to figure out what is going on in the bits in between.
You can start to generate the scale of consciousness. The ability to measure something goes hand in hand with a deeper physical understanding of what that thing is.
And I hope that by starting with some quite crude measure, by applying them in a variety of circumstances we will start to develop a more sophisticated understanding of what consciousness really is, which will then allow us to develop better measuring devices for consciousness, and we will get into a virtuous circle rather than the curious circle.