Self-organized criticality

Birds flock. Locusts swarm. Fish school. From chaotic assemblies of life, order somehow emerges. In this episode, co-host Steven Strogatz interviews the evolutionary ecologist Iain Couzin about how and why collective behaviors arise.

The critical brain hypothesis suggests that neural networks do their best work when connections are not too weak or too strong.

New experimental results simultaneously advance and challenge the theory that the brain’s network of neurons balances on the knife-edge between two phases.

In a renewed attempt at a grand unified theory of brain function, physicists now argue that brains optimize performance by staying near — though not exactly at — the critical point between two phases.

A tiny self-organized mesh full of artificial synapses recalls its experiences and can solve simple problems. Its inventors hope it points the way to devices that match the brain’s energy-efficient computing prowess.

Support is growing for a decades-old physics idea suggesting that localized episodes of disordered brain activity help keep the overall system in healthy balance.