  For the dynamic pitchfork bifurcation in the presence of white noise, the
statistics of the last time at zero are calculated as a function of the noise
level and the rate of change of the parameter. The threshold crossing problem
used, for example, to model the firing of a single cortical neuron is
considered, concentrating on quantities that may be experimentally measurable
but have so far received little attention. Expressions for the statistics of
pre-threshold excursions, occupation density and last crossing time of zero are
compared with results from numerical generation of paths.
