H. Weinberg, Seth Sub- and super-threshold brief stimuli in the AFHN model. <p>(Left) For , indicates the threshold for evoking an action potential. Two trajectories starting near are identified by arrows: (1, left arrow) when the initial condition , returns quickly to the resting potential ; (2, right arrow) when , an action potential is evoked: the system follows a counterclockwise trajectory, quickly approaching the -nullcline, following the right stable branch until reaching the right knee, quickly reaching the left stable branch, and then returning to rest. (Right) When , , the critical value above which an action potential cannot be evoked by a brief perturbation from the steady-state.</p> super-threshold;stimuli;afhn 2013-11-20
    https://plos.figshare.com/articles/figure/_Sub_and_super_threshold_brief_stimuli_in_the_AFHN_model_/858420
10.1371/journal.pone.0081402.g012