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<pre>Hi Everyone,<br> <br>I'm working on an analysis technique which requires that I run 2 ICAs <br>on the same data set. The first is to remove standard eye artifact <br>components, the second to remove components related to other <br>artifacts. I don't use exactly the same data but for the second ICA I <br>use about one third of each trial of the data I use for the first ICA.<br> <br>After listening to the discussions posted here I was wondering whether <br>I should also run a PCA before the second ICA or whether I would not <br>need to do that because I am not using exactly the same data for the <br>second ICA. If I do need to run a PCA, should I reduce the data to <br>the same number of principal components for each subject or could the <br>number of principal components be equal to the number of ICs retained <br>after the first ICA and therefore different for each subject?<br> <br>Many Thanks ...<br><br><br>David Schwartzman<br>Oxford Brookes University<br></pre><br><br><br /><hr />Read amazing stories to your kids on Messenger. <a href='http://clk.atdmt.com/UKM/go/117588488/direct/01/' target='_new'>Try it Now!</a></body>
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