  Stationarity of the constituents of the body and of its functionalities is a
basic requirement for life, being equivalent to survival in first place.
Assuming that the resting state activity of the brain serves essential
functionalities, stationarity entails that the dynamics of the brain needs to
be regulated on a time-averaged basis. The combination of recurrent and driving
external inputs must therefore lead to a non-trivial stationary neural
activity, a condition which is fulfilled for afferent signals of varying
strengths only close to criticality. In this view, the benefits of working
vicinity of a second-order phase transition, such as signal enhancements, are
not the underlying evolutionary drivers, but side effects of the requirement to
keep the brain functional in first place. It is hence more appropriate to use
the term 'self-regulated' in this context, instead of 'self-organized'.
