Between order and chaos
How does our brain manage to process information so extremely efficiently? According to some researchers, a state called "Criticality" may be the key to success.
How exactly our brain's vast network of neurons processes information about the world remains a mystery to neuroscientists. A central piece of the puzzle is the question of how a single physical structure must be designed in order to cope with the myriad demands of life. "If the brain were completely disordered, it would not be able to process any information at all," says Mauro Copelli, a physicist at the Federal University of Pernambuco in Brazil. "However, if it were too ordered, it would lack the flexibility to cope with the diversity of the world."
In the 1990s, the physicist Per Bak hypothesized that the brain derives its amazing abilities from a state called "criticality". The concept comes from statistical mechanics and describes systems that hover between order and chaos. For example, imagine a snowy slope in winter. At the beginning there is only danger from small snow slides, later in the year snow storms can trigger real avalanches. Somewhere between order (solid snowpack) and chaos (snowslide/avalanche) lies a state where anything is possible: the slightest disturbance can trigger a snowslide or an avalanche, or anything in between.
But not all of these events are equally likely. Minor cascades occur exponentially more often than …