<html><head><base href="x-msg://1637/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Sarah,<div><br></div><div>yes, you are correct on both of your points. You may apply the weights calculated on a shorter dataset to a longer dataset and it is (usually) better to apply this procedure than to apply the ICA on the longer dataset with the noise.</div><div><br></div><div>Best,</div><div><br></div><div>Arno</div><div><br><div><div>On 18 Sep 2012, at 10:37, Sara Graziadio wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div lang="EN-GB" link="blue" vlink="purple"><div class="WordSection1" style="page: WordSection1; "><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Thanks a lot for your answers.<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">I wanted just to make sure that I c<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">And also to make sure that it is better to apply this procedure than to apply the ICA on the longer dataset with the noise.<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Best wishes<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Sara<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="border-top-style: none; border-right-style: none; border-bottom-style: none; border-width: initial; border-color: initial; border-left-style: solid; border-left-color: blue; border-left-width: 1.5pt; padding-top: 0cm; padding-right: 0cm; padding-bottom: 0cm; padding-left: 4pt; "><div><div style="border-right-style: none; border-bottom-style: none; border-left-style: none; border-width: initial; border-color: initial; border-top-style: solid; border-top-color: rgb(181, 196, 223); border-top-width: 1pt; padding-top: 3pt; padding-right: 0cm; padding-bottom: 0cm; padding-left: 0cm; "><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><b><span lang="EN-US" style="font-size: 10pt; font-family: Tahoma, sans-serif; ">From:</span></b><span lang="EN-US" style="font-size: 10pt; font-family: Tahoma, sans-serif; "><span class="Apple-converted-space"> </span>Tarik S Bel-Bahar [mailto:tarikbelbahar@gmail.com]<span class="Apple-converted-space"> </span><br><b>Sent:</b><span class="Apple-converted-space"> </span>18 September 2012 04:03<br><b>To:</b><span class="Apple-converted-space"> </span>Sara Graziadio<br><b>Cc:</b><span class="Apple-converted-space"> </span><a href="mailto:eeglablist@sccn.ucsd.edu" style="color: blue; text-decoration: underline; ">eeglablist@sccn.ucsd.edu</a><br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [Eeglablist] ICA question<o:p></o:p></span></div></div></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">A good strategy is to try to clean your data as much<o:p></o:p></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">as possible of extreme artifacts <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">(these extreme artifacts would <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">attract ICA's attention too much).<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Then, if you have enough time points in your data<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">to match ICA's requisites, you should be able<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">to achieve a clean and interpretable ICA decomposition.<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">With ICs that look interpretable in relation to known<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">EEG "components" expected in your protocol.<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">You may also find "real" ICs that you did not expect.<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">The resultant ICA information can then be <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">transferred to a longer continuous file,<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">as you have done. You will however still<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">have to deal with artifactual time periods <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">and artifactual epochs, one way or another.<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">ICA does not care if you give it epochs or continuous data. However it is important that you feed it <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">enough good clean data, data during which <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">the cognitive behavior you are interested in <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">is occurring. In addition to eliminating <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">"artifactual periods" you may also <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">want to eliminate all periods that are not<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">"cognitively"-relevant or "task"-relevant.<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Good luck with your process and let the list know how <o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">things go for you.<o:p></o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><p class="MsoNormal" style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 12pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></p><div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">On Mon, Sep 17, 2012 at 4:26 AM, Sara Graziadio <<a href="mailto:sara.graziadio@newcastle.ac.uk" target="_blank" style="color: blue; text-decoration: underline; ">sara.graziadio@newcastle.ac.uk</a>> wrote:<o:p></o:p></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Hello eeglab users,<br>I have a question about ICA. My data have some noise in some time intervals. I want to remove the noise before using the ICA but I want to have the whole dataset (continuous data, not epoched) to run some more analysis once the data are cleaned with the ICA. Is there a way to do this?<br>At the moment I am running the ICA on the dataset without the noise and then I am applying the ICA weights calculated on the short dataset to the whole dataset (with the noise). Do you think I can do this? Or is there any better method to obtain the whole dataset cleaned without decreasing the ICA performance?<br>Thank you<br><br>Best wishes<br><br>Sara<br><br>Sara Graziadio, PhD<br>Research Associate<br>Institute of Neuroscience<br>Newcastle University<br><br>Address:<br>Sir James Spence Institute<br>Royal Victoria Infirmary<br>Queen Victoria road, NE1 4LP<br>Newcastle upon Tyne, UK<br><br>Tel: <span class="Apple-converted-space"> </span><a href="tel:%2B44%20%280%29191%20282%201377" style="color: blue; text-decoration: underline; ">+44 (0)191 282 1377</a><br><br><br><br><br>_______________________________________________<br>Eeglablist page:<span class="Apple-converted-space"> </span><a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" target="_blank" style="color: blue; text-decoration: underline; ">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>To unsubscribe, send an empty email to<span class="Apple-converted-space"> </span><a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" style="color: blue; text-decoration: underline; ">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>For digest mode, send an email with the subject "set digest mime" to<span class="Apple-converted-space"> </span><a href="mailto:eeglablist-request@sccn.ucsd.edu" style="color: blue; text-decoration: underline; ">eeglablist-request@sccn.ucsd.edu</a><o:p></o:p></div></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div></div></div>_______________________________________________<br>Eeglablist page:<span class="Apple-converted-space"> </span><a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" style="color: blue; text-decoration: underline; ">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>To unsubscribe, send an empty email to<span class="Apple-converted-space"> </span><a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" style="color: blue; text-decoration: underline; ">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>For digest mode, send an email with the subject "set digest mime" to<span class="Apple-converted-space"> </span><a href="mailto:eeglablist-request@sccn.ucsd.edu" style="color: blue; text-decoration: underline; ">eeglablist-request@sccn.ucsd.edu</a></div></span></blockquote></div><br></div></body></html>