The Auto Thresholding feature in Cheetah (v6.1+) gives users a quick way to set a starting threshold value for each spike entity.  Once Auto Thresholding has been applied, you can then begin to fine tune each spike entity's threshold level to your liking.

Auto Thresholding works by analyzing the incoming signal data of each spike entity, taking the mean of the signal data received from each entity, plus the standard deviation of the signal multiplied by the Auto Threshold Multiplier.  This calculation gives you the new threshold level for each acquisition entity independent of the other entities. This also independently adjusts each channel of an entity, meaning each electrode of a tetrode will be set based on its own calculations.

To Auto Threshold a single tetrode, simply select the tetrode of interest from the Acquisition Entities and Display Properties selection tree and click the Run Auto Thresholding button.  You can do a group select and perform the same task on multiple spike entities.

The Auto Threshold Multiplier is set to 2.50 by default.  This value can be set between 0.5 and 5.0.  Depending on your spike activity, different multipliers can provide you with a better auto threshold level.  If there is an excessive amount of noise on a particular electrode, Auto Thresholding may have a difficult time applying a threshold to the electrode.

If you have any questions about this or other features of Cheetah, contact support@neuralynx.com.