<div dir="ltr">Dear Community: <div>My name is Ruoyi.Cao and I am a PhD student in Leon Deouell lab in Hebrew University of Jerusalem. I am currently working on Functional connectivity data during working memory delay. In the experiment, I compared 2 PLV value between two conditions. </div><div>The analysis followed the tutorial </div><div><a href="https://www.fieldtriptoolbox.org/tutorial/connectivity/">https://www.fieldtriptoolbox.org/tutorial/connectivity/</a> </div><div>For the functional connectivity, Instead of coherence, I computed the PLV value. <br></div><div><br></div><div>Here is the step : </div><div>1: I first get fourier coefficient of the data by </div><div>cfg = [];<br>cfg.method = 'mtmfft';<br>cfg.taper = 'dpss';% <br>cfg.output = 'fourier';<br>cfg.tapsmofrq =3<br>cfg.foi = 1:2:60<br>Tapper3freqB2{1} = ft_freqanalysis(cfg, DataB2);<br></div><div><br></div><div>2:Then I put this output </div><div>cfg = [];<br></div><div>cfg.method = 'plv';<br>plvfreqB2 {P} = ft_connectivityanalysis(cfg,
Tapper3freqB2{1}
);<br><br></div><div>Finally, I compared the plv value between conditions and found a robust cluster through cluster-based permutation test. However, I cannot replicate the significant contrast between conditions if I used hanning window with standard fft for calculating fourier coefficient. </div><div><br></div><div>I am writing to ask whether it makes sense to use all the output of multi-tapper method, which is 3 times (taper number is 3) the original trial number to compute the PLV value. What is the influence of the phase estimation that muti-tapper analysis could cause. If the above procedure is not wrong, why the same results can not be replicated with hanning window using one tapper. </div><div><br></div><div>Thank you so much </div><div>Best</div><div>Ruoyi</div><div><br></div><div><br></div><div><br></div><div><br></div></div>