<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear Philip,<div class=""><br class=""></div><div class="">In that case you should consult the function ft_freqbaseline. It offers a variety of ways to normalise the data prior to grand averaging.</div><div class="">Good luck,</div><div class="">tzvetan</div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 6 Mar 2022, at 12:24, philip Joadavi <<a href="mailto:p.joadavi@gmail.com" class="">p.joadavi@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Dear Tzvetan,<div class=""><br class=""></div><div class="">Thanks for your reply. sorry I made a mistake in typing. I meant the function <span style="color:inherit;font-family:SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;font-size:inherit;background-color:rgb(240,240,240)" class="">FT_FREQGRANDAVERAGE</span> (<span style="color:inherit;font-family:SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;font-size:inherit;background-color:rgb(240,240,240)" class="">time-frequency spectrum</span></div><div class=""><span style="color:inherit;font-family:SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;font-size:inherit;background-color:rgb(240,240,240)" class=""> over multiple subjects</span>). I want to average the time-<u class="">frequency</u> spectrum over 11 subjects. For averaging, I want to be sure if the function normalizes the power spectrum for each subject before averaging (to prevent the influence of one subject on the mean value). </div><div class="">do you know if the function (ft_<b class="">freq</b>grandaverage) does this, or is there another function that I need to use for normalizing the time-frequency spectrum for each subject separately?</div><div class=""><br class=""></div><div class="">Thanks a lot!</div><div class="">Philip</div><div class=""><br class=""></div><div class=""> </div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Mar 4, 2022 at 5:26 PM Tzvetan Popov <<a href="mailto:tzvetan.popov@uni-konstanz.de" class="">tzvetan.popov@uni-konstanz.de</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;" class="">Dear Philip,<div class=""><br class=""></div><div class="">The average over subjects is done by ft_timelockgrandaverage. Possible configuration option is cfg.normalizevar = 'N' or 'N-1' (default = 'N-1’). You might consult the help of this function by typing help ft_timelockgrandaverage into the command window.</div><div class="">If by ‘normalisation’ you mean some sort of baseline correction, you should apply ft_timelockbaseline for each participant prior to the average over participants. </div><div class="">Good luck,</div><div class="">tzvetan</div><div class=""><br class=""></div><div class=""><div class=""><br class=""></div><div class=""><br class=""><blockquote type="cite" class=""><div class="">On 4 Mar 2022, at 16:44, philip Joadavi via fieldtrip <<a href="mailto:fieldtrip@science.ru.nl" target="_blank" class="">fieldtrip@science.ru.nl</a>> wrote:</div><br class=""><div class=""><div dir="ltr" class="">Hi all,<div class=""><br class=""></div><div class="">I have a short question for ft_grandaverage. I want to get the average of time frequency results over my subjects, and I was wondering if the function ft_grandaverage does do the normalization over <b class="">subjects</b> when it gets the mean value, or do we need to do the subject normalization separately before calling this function? </div><div class=""><br class=""></div><div class="">Thanks a lot!</div><div class="">Philip</div></div>
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