  Humans face the task of balancing dynamic systems near an unstable
equilibrium repeatedly throughout their lives. Much research has been aimed at
understanding the mechanisms of intermittent control in the context of human
balance control. The present paper deals with one of the recent developments in
the theory of human intermittent control, namely, the double-well model of
noise-driven control activation. We demonstrate that the double-well model can
reproduce the whole range of experimentally observed distributions under
different conditions. Moreover, we show that a slight change in the noise
intensity parameter leads to a sudden shift of the action point distribution
shape, that is, a phase transition is observed.
