From John Harris, Richmond, North Yorkshire, UK
While reading your article on the potentially unstable brain, I was reminded of a close parallel: controlling the Eurofighter Typhoon, a modern jet fighter. In essence, the plane is aerodynamically unstable and requires computer input to function. However, the gain is that the plane is more manoeuvrable and more agile. The key point is that there is no preferred state that would tend to oppose a change of speed or direction. The same might well be true of the brain: balanced on the edge of criticality, without a preferred state, it can respond rapidly to any challenge(6 September, p 30).
