User`s manual

Cerebus® User’s Manual
Revision 13.00 / LB-0028 Page 37
o Close Peak Percentage: For a second peak to be found, the second peak height needs to be greater than the height of the
valley + the height of the 3 points around the peak * the close peak percentage (second peak height > valley height +
(3-point mean around valley * close peak percentage)).
o Freeze Time (minutes): Time Specified in minutes that the spike-sorting process of determining the number of units per
channels runs.
o Update Rate (# spikes): Specifies the number of spikes that needs to be collected per unit before spike-sorting statistics
are updated. Assume one unit per channel at the beginning.
o Minimum Peak Percentage: Histogram peaks have to have a minimum height which is calculated by adding the valley
height (or zero) to the value of total # of samples used * minimum peak percentage.
o Method Manual PCA: Uses Principle Component Analysis method to sort units recorded on an electrode.
o Wave Basis Size: The number of waveforms to use to calculate the PCA basis vectors. Example, 250 waveforms are
needed to create the PCA basis vectors.
o Update Basis Multiplier: The multiplier of the basis size. This number is used to recreate the basis after so many
waveforms. For example, if this number is 5 and the Wave Basis Size is 250 then after 1250 (250 x 5) waveforms the
PCA basis vectors are recalculated.
o Artifact Rejection: This feature is used to reject spike events that occur simultaneously across multiple channels.
o Maximum Simultaneous Channels: If more than X channels contain simultaneous spike events, the events are rejected
and are not use in spike sorting and the corresponding waveforms are not recorded in the NEV file.
o Refractory Period: Spike detection is turned off for X samples after an event has been detected.