AcqKnowledge includes digital filters that allow you to filter a raw EEG into the following frequency bands:
Gamma 36-90Hz (in some older versions the upper frequency is 44 Hz)
The filters may be selected and then modified for different frequency bands if desired.
From the MP menu, select “Set Up Channels…” (in version 4.4, choose “MP150 > Set Up Data Acquisition…” and select “Channels” in the pane on the left) and click the “Calc” radio button (version 3.9 or earlier) or “Calculation” tab. From the calculation channel presets menu, select the appropriate frequency band and click the “Setup…” button
From the Filter setup dialog, select the correct EEG “Source” channel, change the frequency range if desired, and click “OK”
When you start to record data you will see additional channels that contain band pass filtered versions of the raw EEG data.
Select the raw EEG channel
From the “Edit” menu, choose “Select All”
From the “Edit” menu, select “Duplicate Waveform” to create a new channel
From the “Transform menu”, select “Digital filters”, then “IIR”, and then ” Band Pass Low + High”
From the Band Pass dialog box, set the Low and High frequency cutoff values to match one of the frequency bands listed above, and click “OK”
- Repeat the above steps for other frequency bands
AcqKnowledge version 3.9.1 and above for Macintosh and version 4.0 and above for Windows fully automate the offline procedure for creating these additional channels. Choose “Analysis > Electroencephalography > Derive EEG Frequency Bands” and follow the on-screen prompts.
Page last modified 24Dec2014
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