User manual

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4.5.4 Erase Raw, Averaged, Blanked Traces if Low-Pass Filtering
If you are using an amplifier which does not have low-pass filtering to record your synaptic activity (such
as several intracellular amplifiers), there is no low-pass filtering to remove excess noise that is necessary
for correct analysis of many parameters such as peak amplitude. Provided there is sufficient external
anti-aliasing filtering at half or less the sample frequency (say 10 KHz external low-pass filtering for a
20KHz sample frequency, see Section 2.14), you can use the internal digital low-pass filter in WinLTP to
do the additional low-pass filtering (Section 4.5.4) necessary for correct analysis.
However, the resulting trace is cluttered with the unnecessary raw trace. Fig. 4.5.4.1 shows the effect of
using the “Erase Raw/Averaged/Blanked Traces if Filtering” check box to remove the unnecessary,
cluttering raw trace.
When additional internal low-pass filtering is used, if the
[ ] Erase Raw/Averaged/Blanked Traces if Filtering
check box is not checked (red arrow in top panel), the raw (gray) trace is unnecessarily shown as well as
the necessary 1000 Hz low-pass filtered (blue) trace (top panel). However if the “Erase
Raw/Averaged/Blanked Traces if Filtering” check box is checked, only the uncluttered low-pass filtered
(blue) trace is shown (bottom panel).