The human brain consists of about 100 billion neurons and 100 trillion connections between those neurons. Each neuron is relatively simple (compared to the whole brain) and there is no central control. Somehow the huge ensemble of neurons and connections gives rise to the complex behaviors we call “cognition” or “intelligence” or even “creativity”.

Brain imaging has shown that these neurons have organized themselves into different functional areas. Just like ants or termites (other examples of complex systems), neurons can self-organize into complex structures that help the species function and survive.