Multichannel Systems MC_Rack Manual - Manual (Page 148)

MC_Rack Manual
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4.13 Spike Sorter
4.13.1 Spike Detection Methods
The virtual Spike Sorter instrument is used for extracting spikes from the raw data,
and for sorting spikes into up to three single units per electrode (channel).
There are two ways of detecting and extracting spikes with MC_Rack. One method uses
a threshold, the other recognizes the shape, that is, the amplitude and slope of a curve.
Both methods regard either the rise or the fall of a curve, depending on your settings.
Waveforms that meet the requirements defined by either of the two methods are cut out
from the raw data. The size of the cutout, that is, the time length before and after the spike
detection event, can be chosen by the user. It is also possible to extract only the time stamps.
The Threshold method is especially useful if the overall signal is steady and the spikes appear
approximately on the same height. If you have local field potentials or a high noise level,
you will miss spikes or detect noise signals with the Threshold method. In this case, the Slope
method is more appropriate.
The following illustrations show how the two methods work.