One of the curious properties of brain activity — the firing of neurons — is that it follows certain patterns. One of these is that brain activity tends to be maintained rather than dampened or amplified.
This turns out to be a special phenomenon of self-organization. Active neurons tend to trigger other neurons. If each active neuron triggers more than one other, any activity is rapidly amplified in a chain reaction. If each neuron triggers less than one other, the activity tends to fizzle out, like a damp firework.
But to maintain activity, each active neuron must trigger about one other neuron. Neuroscientists call this criticality and believe that it maximizes the flow of information through a neural network.
Most healthy brain activity seems to occur in this special critical state.
And that raises an interesting question. Brain function changes substantially as we age. Older people tend to be more ...
