<div dir="ltr"><div><div><div>Dear Mick,<br><br></div>How did the designmatrix for ft_freqstatistics look? Maybe something went wrong there.<br><br></div>Cheers,<br></div><div>Stephen<br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 27 July 2015 at 18:24, <span dir="ltr"><<a href="mailto:mick.lehmann@uzh.ch" target="_blank">mick.lehmann@uzh.ch</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><font face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" size="2"><font face="Verdana, Arial, Helvetica, sans-serif">Dear Fieldtrippers,</font><div style="font-family:Verdana,Arial,Helvetica,sans-serif"><br></div><div style="font-family:Verdana,Arial,Helvetica,sans-serif">I did the baseline correction using the following script:</div><div style="font-family:Verdana,Arial,Helvetica,sans-serif"><br></div><div><div><font face="Verdana, Arial, Helvetica, sans-serif"> TF_Remem_low = ft_freqbaseline(cfg, TF_Remem)</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"> cfg.baseline = [-1 -.1 ];</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"> cfg.baselinetype = 'relchange'; HERE, I'VE TRIED 'DB' AND 'RELCHANGE', THE OUTCOME DIDN'T DIFFER</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"> cfg.parameter = 'powspctrm';</font></div></div><div><font face="Verdana, Arial, Helvetica, sans-serif"><br></font></div><div><font face="Verdana, Arial, Helvetica, sans-serif">This was done after </font><span style="font-family:Verdana,Arial,Helvetica,sans-serif;font-size:12.8000001907349px">ft_freqanalysis and before calculating the grand average. </span></div><div><span style="font-family:Verdana,Arial,Helvetica,sans-serif;font-size:12.8000001907349px"><br></span></div><div><font face="Verdana, Arial, Helvetica, sans-serif">During the trial definition, I've already specified the baseline window and used 'demean':</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"><br></font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"><span style="white-space:pre-wrap"> </span>cfg.demean = 'yes';</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"><span style="white-space:pre-wrap"> </span>cfg.baselinewindow = [-1 -.1];</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"><br></font></div><div><font face="Verdana, Arial, Helvetica, sans-serif">When I made the figure for a contrast, it looked fine and exactly as I expected (see attachment). However, calculating the statistics using the cluster-based permutation test over a time window of 0-2000ms and between 5 and 7 Hz (without averaging for time and frequency range), the comparison between the two conditions for every single time and frequency bin was highly significant (p< 0.001). This observation is not congruent with the figure, especially the fact that the t-values are almost equal across the 2 seconds and across the freq range.</font></div><div><font face="Verdana, Arial, Helvetica, sans-serif"><br></font></div><div><font face="Verdana, Arial, Helvetica, sans-serif">Does anybody have an idea what might be the problem? Are the provided details sufficient for understanding the procedure?</font></div><div><br></div><div>Here the script for the cluster-based permutation:</div><div><div><br></div><div>cfg = [];</div><div>cfg.channel = 'all';</div><div>cfg.latency = [0 2];</div><div>cfg.avgovertime = 'no';</div><div>cfg.frequency = [5 7];</div><div>cfg.avgoverfreq = 'no';</div><div>cfg.method = 'montecarlo'; </div><div>cfg.statistic = 'ft_statfun_depsamplesT';</div><div>cfg.correctm = 'cluster';</div><div>cfg.clusteralpha = 0.001;</div><div>cfg.clusterstatistic = 'maxsum';</div><div>cfg.minnbchan = 2;</div><div>cfg.tail = 0;</div><div>cfg.clustertail = 0;</div><div>cfg.alpha = 0.001;</div><div>cfg.numrandomization = 1000;</div><div><span style="font-size:12.8000001907349px">cfg.neighbours = neighbours;</span></div></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">I'm deeply grateful for every comment.</span></div><div>Best regards,</div><div>Mick</div><div></div></font><br>_______________________________________________<br>
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