Observation of saddle-point avoidance in noise-induced escape

The first measurements of an exit location distribution are reported for an overdamped nonconservative system perturbed by weak white noise, modeled b oth numerically and by an analog electronic circuit. in the weak-noise limi t the distribution is increasingly concentrated near a saddle point of the dynamics and is increasingly well approximated by a Weibull distribution, i n agreement with theoretical predictions. A physical explanation for this b ehavior is given, which should facilitate the computation of corrections to the limiting form. [S0031-9007(99)08581-6].