<div dir="ltr"><div class="gmail_default" style="color:rgb(51,51,153)"><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">Hi Becky, </div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">
<br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">well, hopefully you have some nice ICs after feeding ICA quality data that is clean and long enough.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">
some quick responses to your queries below, good luck with the processing.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">
<br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">1. Wait to reject artifactual ICs till after you transfer them over to EEG2. Order matters as I believe you'll not have matching channels between the two files unless you seek out and remove those same channels from EEG2 before copying the ICA fields over from EEG1.</div>
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2. Yes, reject those same channels. You can interpolate the channels later for EEG2.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">What I usually do for an erp paradigm is have a file that is totally cleaned of bad periods, then I drop all bad channels, then I epoch, then I feed to ICA.</div>
<div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">Then EEG1 with ICA can be applied the step right after dropping the bad channels (if you save a file at that step).</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">
Order matters, because the channels of the file that is getting the ICA should match exactly the channels of the file with the ICA.<br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">
<br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:13px">Regarding running ICA only on good channels, some good rules of thumb are don't drop more than 20% of your channels, don't replace bad channels with data from surrounding bad channels, watch out for clusters of bad channels and note that it's not good to interpolate clusters of adjacent bad channels. Some of these points of course vary depending on whether you work with a 16 channel montage or a 256 or better channel montage</div>
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<br><br><div class="gmail_quote">On Mon, Dec 2, 2013 at 10:37 AM, Becky Prince <span dir="ltr"><<a href="mailto:becky.prince@york.ac.uk" target="_blank">becky.prince@york.ac.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div dir="ltr">Dear EEGLAB users,<div><br></div><div>I ran ICA on clean, epoched subsets of my individual data sets with the goal of using the ICA decomposition from each subject on their larger continuous data set. So for each subject, I have a cleaned, epoched, smaller EEG set with ICA (EEG1) and a larger, continuous EEG set without ICA (EEG2). Now I'd like to copy each subject's ICA info from EEG1 into EEG2, and continue analysis on the EEG2 data sets for each subject.</div>
<div><br></div><div>I have a few questions:</div><div><br></div><div>1. Should I reject the artifactual ICs before or after copying the ICA fields into the EEG2 data set? Does the order of these steps matter?<br></div><div>
<br></div><div>2. If there are fewer channels in EEG1 (set with ICA), should I reject the same channels in EEG2 before copying the ICA fields into the EEG2 data structure? Again, does the order of these steps matter? </div>
<div><br></div><div>BTW I have been reading the previous posts about rejected/interpolated channels and ICA, so I'm somewhat familiar with the issues running ICA on only the 'good' channels. </div><div><br></div>
<div>Thanks!</div><div>Becky</div><div><div><div dir="ltr"><span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">______________________________</span><span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">______________</span><br style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Becky Gilbert (nee Prince)</span><br style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">PhD Researcher</span><div><br></div><div><a href="http://www.york.ac.uk/psychology/staff/postgrads/becky.gilbert/" target="_blank">http://www.york.ac.uk/psychology/staff/postgrads/becky.gilbert/</a><br style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Office B213</span></div><div>Lab C120<br><div><span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Department of Psychology</span><br style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">University of York</span><div><span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Heslington, York, YO10 5DD, UK</span><br>
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