Net Station Waveform Tools - College of Education & Human ...

1: The Waveform Tools Window
Tips on Using Waveform Tools
When you start analyzing data from an experiment, it usually takes some trial and
error to find the order of operations and parameters that is best for you. To determine
your optimal data-analysis path, it is advisable first to process the data from a single
subject carefully to:
• verify that you can do what you want to do (you may learn that you need to
modify your experimental control script)
• learn the effects of the various operations and their parameters
As described in Chapter 7, “ERP Derivation and Waveform Tools,” of the Net Station
Viewer and Waveform Tools Tutorial, the normal order of the performing Waveform
Tools operations to derive a single-subject ERP is:
• Filtering,
• Segmentation,
• Artifact Detection,
• Bad Channel Replacement,
• Averaging,
• Average Referencing, and
• Baseline Correction.
We strongly recommend filtering your data before segmenting them. Although we
offer a Waveform Tool for filtering short epochs, it is not as accurate as the Filtering
tool (described in Chapter 12, "Filtering”).
Caution!: Before averaging, make sure that you have assigned a subject to the file
to ensure that the subject information remains available for subsequent Waveform
Tools operations such as Averaging, Combine Files, and Statistic Extraction.
Assigning a subject after averaging is not recommended. The following section,
“Assigning Subjects,” discusses this topic in more detail.
Once you have processed the data from one subject, you can process the data from the
remaining subjects in a more automated fashion by using the Script tool.
Once you have ERPs from several subjects, you can create grand-average ERPs. You
should use non-baseline-corrected data for grand averaging so that you can
understand the effects of baseline correction on your grand-average ERPs.
28 Net Station Waveform Tools Technical Manual S-MAN-200-WFTR-001 • December 21, 2006