Affects: automatic selection of single-unit spike data
This parameter is used only when automatically setting single-unit data, to further eliminate spikes not rejected by the basic threshold-hysteresis-discriminator spike detection algorithm.
Unlike the first "Spike discriminator" parameter, which rejects spikes that are too high, the second discriminator checks how far the spike recoils in the other direction after the initial peak (i.e. the strength of the AHP following the action potential). The signal is scanned from the spike onset, through to its fall below the "Spike baseline", and up until it rises above the baseline again. If it dips below this discriminator level at any time, the spike is rejected.
If the hysteresis is positive (above the threshold), the program will search for negative going spikes. In this case, the concepts of "rise" and "fall" are reversed, so the discriminator selects the maximum allowed recoil height, rather than the minimum.
|Key sequence||Parameter||Initial Value|
|<Esc>Wn<CR>SSUD||Second spike discriminator||0 mV|