Baseline, Artifact Removal or Filtering on Absolute Values?

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icetea
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Joined: Fri Apr 17, 2020 6:37 pm

Baseline, Artifact Removal or Filtering on Absolute Values?

Post by icetea »

Hi,

I am a beginner, so please bear with my questions. I am wondering if the following are already done for the Absolute values:
1. Baseline removal
2. Artifact removal (for example, if one of the sensors weren't recording, would that data point be excluded; or would jaw clenching data points be
excluded)
3. Filtering (Any high or low pass)

I'd appreciate any help or guidance towards documentation.

Thanks!
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James
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Joined: Wed Jan 02, 2013 9:06 pm

Re: Baseline, Artifact Removal or Filtering on Absolute Values?

Post by James »

#1 - I'm not sure what baseline removal is, sorry.
#2 - I believe Interaxon's code removes blinks and jaw clenching. Each sensor has a independent brainwave values. In the live view, the average is shown by default, excluding sensors which are marked on the HSI as bad. In the settings you can toggle between the average and each individual value. In the recorded and streamed data, you will get everything.
#3 - Yes. There's powerline filtering applied to the brainwaves, you can change this in settings to switch between 50/60Hz.
icetea
Posts: 4
Joined: Fri Apr 17, 2020 6:37 pm

Re: Baseline, Artifact Removal or Filtering on Absolute Values?

Post by icetea »

Many thanks! These helps a ton!

By baseline removal, I meant subtracting the baseline values of each user from their data so that if someone has high baseline (when relaxed) values and someone has low baseline values we could still compare the difference in their results. The correct term may be baseline correction.
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James
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Re: Baseline, Artifact Removal or Filtering on Absolute Values?

Post by James »

Ok, so no baseline removal. Values are always calculated from RAW EEG values from scratch each time.
icetea
Posts: 4
Joined: Fri Apr 17, 2020 6:37 pm

Re: Baseline, Artifact Removal or Filtering on Absolute Values?

Post by icetea »

Got it, thanks a lot!
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