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<div class="moz-cite-prefix">Hi Julia,<br>
<br>
I've seen the before as well and my personal theory is that they
are due to common mode noise (though I don't have direct proof).
If you change your data to using a common average reference, I
think they should go away. That would also explain why your data
looks cleaner without them, as you are essentially removing the
common mode noise (albeit in an roundabout way).<br>
<br>
Luca<br>
<br>
On 04/05/2017 08:24 AM, Julia Basso wrote:<br>
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<div dir="ltr"><span style="font-size:12.8px">Dear all,</span>
<div style="font-size:12.8px"><br>
</div>
<div style="font-size:12.8px">I have a 20 channel EEG system and
after cleaning the data by first conducting a band pass filter
than cleaning epoched data by visual inspection, I am running
ICA to detect and remove eye blinks and eye movements. </div>
<div style="font-size:12.8px"><br>
</div>
<div style="font-size:12.8px">My question is in regards to ICs
that are distinctly all blue or all red. <span
style="font-size:12.8px">My instinct is to remove these ICs
(and when I do, the data looks cleaner)- but I wanted to get
your opinion. What does this type of IC indicate? Is it
merely noise in the system?</span></div>
<div style="font-size:12.8px"><br>
</div>
<div style="font-size:12.8px">Best,</div>
<div style="font-size:12.8px"><br>
</div>
<div style="font-size:12.8px">Julia</div>
<div><br>
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-- <br>
<div class="gmail_signature">
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<div dir="ltr"><i>Julia C. Basso, PhD, CYT</i>
<div><i>Post-doctoral Research Associate</i></div>
<div><i><br>
</i></div>
<div><i>New York University</i></div>
<div><i>Center for Neural Science</i></div>
<div><i>Suzuki Laboratory</i></div>
<div><i>4 Washington Place, Room 809</i></div>
<div><i>New York, NY 10003</i></div>
<div><i>(212) 998-3969</i></div>
<div><span style="font-size:12.8px"><a
moz-do-not-send="true"
href="http://www.juliabasso.com"
target="_blank">www.juliabasso.com</a></span></div>
<div><i style="font-size:12.8px"><a
moz-do-not-send="true"
href="http://www.suzukilab.com"
target="_blank">www.suzukilab.com</a></i></div>
<div><br>
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