Sync: How Order Emerges from Chaos In the Universe, Nature, and Daily Life

"Steven Strogatz is a wonderful scientist. He is both a mathematician and a physicist. He’s done a lot of work on understanding non-linear systems. The reason I’ve chosen this book is that if we really want to understand the language of the brain we have to engage with these very powerful concepts of how it is that things are synchronised, how it is that they oscillate together. This is a book for the general public that tries to relay some of that excitement, some of the tools that we’ve gained mathematically in order to do that. He starts with fireflies. You will have seen them at night, when they are fluctuating and synching. One of his great discoveries is that if you put each of them in their own little cup, they will go into their own frequencies and be completely out of sync with one another. But all you have to do is to remove the cup, and suddenly, spontaneously, they will start to sync again: they will go into patterns that will be weaving in and out. This is exactly how the brain works. Understanding that — and the physics and the mathematics of doing that — is what allows us to create models and go beyond being new phrenologists, beyond just saying ‘Well, something happened and that went off and that went off.’ Instead, we can make models which divide the brain into a couple of hundred different regions and we work out exactly what the wiring is between them. We can create a sort of skeleton of where this communication can happen. Then we watch the communication unfold, and we make computational models that can mimic that. At each stage, we put in these synchronous, these oscillatory abilities, and we can then recreate what the human brain is doing. More importantly, we can then go back to the model and say ‘Okay so that part correlated with this. What happens if I take that out of my model? Will I still get the same result or will I get something different? If I take it out and get the same result then I can say that it’s probably not causally related. But if I take it away and the model gives a different answer, I can say that this part is in fact what is causing the synchronisation. Yes. What I’m suggesting is that if we are serious about understanding mood, and if we want to understand how emotions malfunction, as they often do, and how the brain becomes unbalanced, what we need to understand is that even if we have the same network, the traffic can flow in many different ways. Look at how traffic runs: if a certain hub is suddenly working at only 20% of capacity, you can get a road jam somewhere else. If we want to try and clear up that road jam, and rebalance the brain, the only way of doing that is to understand the mathematics. What he is proposing here shows how that can be done in a very elegant and accessible way that many people will be able to relate to. What is also clear from his work is that the brain is a special kind of network, it has certain properties that allow all these interesting things to happen. It allows things like emotion to guide and to explore the repertoire, if you like, of the system. Emotions can be thought of as guidance as to why it is that we should explore this part as opposed to that part. The big question becomes: when do things change? When do we have phase transitions? Everybody will be familiar with phase transitions. Take water. If you heat it up over a hundred degrees, suddenly you have vapour. If you freeze it to zero, you have ice. It’s the same thing with the human brain. Depending on different conditions, you have radically different states. You can be awake or you can be asleep, you can be functioning normally or you can be manic. What is it that is causing those phase transitions?"