<html><head><base href="x-msg://1696/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Francesco,<div><br></div><div>first I would be careful about applying ICA outside of EEGLAB. Most commercial software packages preprocess the data using PCA (so you do not have to review all the components) with often dramatic effects on ICA component quality. PCA should not be used before ICA unless it is absolutely necessary.</div><div><br></div><div>Second in the code provided on the wiki, you might want to average the ERP scalp topography over a time range rather than picking a single sample point (in this case 100 ms) before performing source localization.</div><div><br></div><div>I hope this helps,</div><div><br></div><div>Arno</div><div><br><div><div>On 18 Feb 2013, at 00:24, Francesco Sigona 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 text="#000000" bgcolor="#FFFFFF"><span id="result_box" class="" lang="en"><span class="hps">Hello guys</span><span>,<br><br>I recently</span><span class="Apple-converted-space"> </span><span class="hps">started using</span><span class="Apple-converted-space"> </span><span class="hps">eeglab</span><span class="Apple-converted-space"> </span><span class="hps">with which</span><span class="Apple-converted-space"> </span><span class="hps">I would like to</span><span class="Apple-converted-space"> </span><span class="hps">carry out</span><span class="Apple-converted-space"> </span><span class="hps">a dipole fitting</span><span class="hps"><span class="Apple-converted-space"> </span>on ERPs data (N100).</span><br><span class="hps">I usually use</span><span class="Apple-converted-space"> </span><span class="hps">BrainVision</span><span class="Apple-converted-space"> </span><span class="hps">Analyzer</span><span class="Apple-converted-space"> </span><span class="hps">to work with</span><span class="Apple-converted-space"> </span><span class="hps">ERPs</span><span>, but</span><span class="Apple-converted-space"> </span><span class="hps">this</span><span class="Apple-converted-space"> </span><span class="hps">software cannot do</span><span class="Apple-converted-space"> </span><span class="hps">the<span class="Apple-converted-space"> </span></span><span class="hps">dipole localization.<br><br></span><span class="hps">I</span><span class="Apple-converted-space"> </span><span class="hps">cleansed</span><span class="Apple-converted-space"> </span><span class="hps">the signals with</span><span class="Apple-converted-space"> </span><span class="hps">ICA</span><span class="Apple-converted-space"> </span><span class="hps">(on</span><span class="Apple-converted-space"> </span><span class="hps">BrainVision</span><span class="Apple-converted-space"> </span><span class="hps">analyzer)</span><span>, I ran</span><span class="Apple-converted-space"> </span><span class="hps">an average</span><span class="Apple-converted-space"> </span><span class="hps">of the different epoques<span class="Apple-converted-space"> </span></span><span class="hps">and</span><span class="Apple-converted-space"> </span><span class="hps">I imported</span><span class="Apple-converted-space"> </span><span class="hps">the data</span><span class="Apple-converted-space"> </span><span class="hps">(65</span><span class="Apple-converted-space"> </span><span class="hps">sensors</span><span>, 70</span><span class="hps">time points</span><span>)</span><span class="Apple-converted-space"> </span><span class="hps">in</span><span class="Apple-converted-space"> </span><span class="hps">eeglab</span><span>.</span><span class="Apple-converted-space"> </span><span class="hps">Then I followed</span><span class="Apple-converted-space"> </span><span class="hps">the tutorial about<span class="Apple-converted-space"> </span></span><span class="hps">dipfit (<a class="moz-txt-link-freetext" href="http://sccn.ucsd.edu/wiki/A08:_DIPFIT#Using_DIPFIT_to_fit_EEG_or_ERP_scalp_maps">http://sccn.ucsd.edu/wiki/A08:_DIPFIT#Using_DIPFIT_to_fit_EEG_or_ERP_scalp_maps</a>)</span><span class="Apple-converted-space"> </span><span class="hps">but I have not</span><span class="Apple-converted-space"> </span><span class="hps">got encouraging results</span><span>.</span><br><span class="hps">For this reason</span><span class="Apple-converted-space"> </span><span class="hps">I ask you</span><span class="Apple-converted-space"> </span><span class="hps">some indication of the</span><span class="Apple-converted-space"> </span><span class="hps">method to be followed</span><span>, if it is</span><span class="Apple-converted-space"> </span><span class="hps">necessary or not</span><span class="Apple-converted-space"> </span><span class="hps">perform</span><span class="Apple-converted-space"> </span><span class="hps">dipfit</span><span class="Apple-converted-space"> </span><span class="hps">of</span><span class="Apple-converted-space"> </span><span class="hps atn">ICA (</span><span>but</span><span class="Apple-converted-space"> </span><span class="hps">which components</span><span><span class="Apple-converted-space"> </span>and how should be selected?) or</span><span class="Apple-converted-space"> </span><span class="hps">can I use</span><span class="Apple-converted-space"> </span><span class="hps">dipfit_erpeeg</span><span>.</span><br><span class="hps">I really hope</span><span class="Apple-converted-space"> </span><span class="hps">in</span><span class="Apple-converted-space"> </span><span class="hps">a</span><span class="Apple-converted-space"> </span><span class="hps">help.</span><br><span class="hps">Thanks in advance</span><span>.</span><br></span><br><pre class="moz-signature" cols="72">--
Francesco Sigona
CRIL - Università del Salento
via Pappacoda, 12
73100, Lecce - Italy
web: <a class="moz-txt-link-freetext" href="http://www.cril.unisalento.it">http://www.cril.unisalento.it</a>
tel.: +39 0832 332097
fax.: +39 0832 252570
</pre>_______________________________________________<br>Eeglablist page:<span class="Apple-converted-space"> </span><a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html">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">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">eeglablist-request@sccn.ucsd.edu</a></div></span></blockquote></div><br></div></body></html>