<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1500709388977_21980"><div style="background-color: inherit; display: table; width: 567px; padding-top: 12px; padding-left: 0px;" id="yui_3_16_0_ym19_1_1500709388977_22051"><div style="display: table-cell; width: auto; word-wrap: break-word;" id="yui_3_16_0_ym19_1_1500709388977_22052"><div id="yui_3_16_0_ym19_1_1500709388977_22053"><div id="yui_3_16_0_ym19_1_1500709388977_22054"><div id="yui_3_16_0_ym19_1_1500709388977_22055"><div dir="ltr" id="yui_3_16_0_ym19_1_1500709388977_22056"><div dir="ltr" style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22057">Hello,</div><div dir="ltr" style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22063"><br id="yui_3_16_0_ym19_1_1500709388977_22064"></div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22065"> I’m doing a project on the effects of music on the functional connectivity of the brain using EEG. But l came across a confusing problem during preprocessing of my data!</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22066">We all know that there isn’t a confirmed and stable pipeline for preprocessing so that all experts agree on. So I tried two different ways to preprocess my data that l’ve explained below but adding to the confusion is the fact that after finishing preprocessing and doing the main process, data acquired by each of these two ways gave me completely different results and now l wonder which of these ways and subsequently final results could be correct!!</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22067"><br id="yui_3_16_0_ym19_1_1500709388977_22068"></div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22069"> but first l want to give you a little about my data and process. I took a 32-channel continuous data of length 350000 datapoints from each person(my subjects are children between 10 to 13 years old). These data consist of 12 segments during which 12 music excerpts was played. The lengths of these 12 segments vary between 12000 And 27000 datapoints. As you can see below the only major difference between these two pipelines that l’ve taken is doing segmentation as the final step or doing it earlier!! My reason to abandon the first way and trying the second was the fact that the final segments in first way, after doing all of these steps and after segmentation were sometimes noisy and had noisy channels that made me confused!!</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22070"> And now the two ways l took to clean the data and prepare it for the final process:</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22071"><br id="yui_3_16_0_ym19_1_1500709388977_22072"></div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22073"><b id="yui_3_16_0_ym19_1_1500709388977_22074"><u id="yui_3_16_0_ym19_1_1500709388977_22075">First way:</u></b></div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22076">Define channel location file</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22077">Band-pass filter between 1 to 40 Hz</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22078">Rejection of paroxysmal artifacts</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22079">Remove bad channels</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22080">Run ICA</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22081">Run ADJUST toolbox to find bad components</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22082">Interpolate removed channels</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22083">Re-reference to average</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22084">Segmentation</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22085"> </div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22086"><b id="yui_3_16_0_ym19_1_1500709388977_22087"><u id="yui_3_16_0_ym19_1_1500709388977_22088">second way:</u></b></div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22089">Define channel location file</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22090">Band-pass filter between 1 to 40 Hz</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22091">Segmentation</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22092"><b id="yui_3_16_0_ym19_1_1500709388977_22093">And doing these works on each segment</b>:</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22094">Remove paroxysmal artifacts</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22095">Remove bad channels (but l didn’t remove if bad channels were fp1 and fp2 because l thought they were bad channels because of eye blinks and eye movements (by visual inspection) that ICA would remove them properly and data after running ICA and ADJUST showed me that l thought correct)</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22096">Run ICA</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22097">Run ADJUST</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22098">Interpolate if there were removed channels</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22099">Re-reference to average</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22100">Re-checking the data for residual artifacts</div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22101"> </div><div style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22102">Whether my reason to not remove bad channels if they are due to eye movements and running ICA on them is correct?</div><div dir="ltr" style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22103">And how can l get sure that my process is correct and the data are really clean?</div><div dir="ltr" style="text-align: justify;" id="yui_3_16_0_ym19_1_1500709388977_22104"><br id="yui_3_16_0_ym19_1_1500709388977_22105"></div></div><div dir="ltr" id="yui_3_16_0_ym19_1_1500709388977_22106">l would be very grateful for your kind help. </div></div></div></div></div></div><div id="yui_3_16_0_ym19_1_1500709388977_22113"></div></div><div></div><div id="yui_3_16_0_ym19_1_1500709388977_21979" dir="ltr"> </div><div class="signature" id="yui_3_16_0_ym19_1_1500709388977_22114">Best regards,<div id="yui_3_16_0_ym19_1_1500709388977_22161">Zhaleh </div><div id="yui_3_16_0_ym19_1_1500709388977_22162"><br></div></div></div></body></html>