Appendix 1—figure 8. Supercritical Hopf onset and offset. This is the seizure from Figure 2D.

Here, the terminal ISI is nearly constant and does not have any ‘slowing down.’ The amplitude, on the other hand, clearly diminishes and trends to zero as a square root power law by the end of the seizure. There are even some potential smaller spikes seen after the seizure (*), as if the spikes have vanished into the background noise. In this case, the seizure stops because the amplitude, rather than the frequency, has gone to zero. The constant ISI and diminishing amplitude are indicative of the SupH offset. The same pattern occurs at onset. Offset Classification: DC shift: no. Amplitude decreasing: yes. This is a SupH offset. The ISI is also constant, which is consistent but not necessary for the classification due to prioritization. Onset Classification: DC shift: no. Amplitude increasing: yes. This is a SupH onset.