<div dir="ltr">Hi Viotira,<div> If you don't care about time information , you can average it by specifying cfg.avgovertime = 'yes' on the TFR , then the cluster will be formed in channel-frequency format. If you use mtmfft , you should pre-select effect interval . Otherwise, it could be not consistent .</div>
<div> Best,</div><div> Haiteng</div><div> </div><div> </div>
<div> </div><div> <br><div class="gmail_extra"><br><br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<br>
Message: 1<br>
Date: Sun, 13 Apr 2014 18:53:10 -0700<br>
From: Vit?ria Piai <<a href="mailto:v.piai.research@gmail.com">v.piai.research@gmail.com</a>><br>
To: FieldTrip discussion list <<a href="mailto:fieldtrip@science.ru.nl">fieldtrip@science.ru.nl</a>><br>
Subject: [FieldTrip] freqstatistics with sbj_chan_freq<br>
Message-ID: <<a href="mailto:534B3F86.9070904@gmail.com">534B3F86.9070904@gmail.com</a>><br>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"<br>
<br>
Hi all,<br>
<br>
I'm kinda stuck not being able to figure out what's going wrong with my<br>
freqstats, so I thought I could share it here and see if anyone can see<br>
where I'm going wrong.<br>
When I run freqstatistics on TFRs, I get a negative cluster (p = .001)<br>
between 8 and 25 Hz with the topography very similar to the one in the<br>
figure. But I just want non-time-resolved spectra.<br>
So I have power spectra calculated with mtmfft (dpss tapers) between 1<br>
and 50 Hz (5 Hz smoothing) and this is the one for which I've been<br>
trying to run freqstatistics, unsuccessfully.<br>
I'm using a pretty standard cfg for freqstats (basically, the same I use<br>
for the TFRs, which give me the negative cluster with p =.001) and the<br>
data in the comparison are structured as sbj_chan_freq. With this<br>
time-unresolved data, only posclusters are detected, with ps > .4! If I<br>
plot the stat output, it has the exact same negative cluster as I get<br>
for the TFRs (see Figure), and as far as I can see, no real positive<br>
cluster, but the function doesn't even detect any negative clusters.<br>
I must be doing something wrong because the time-resolved and<br>
-unresolved effects are pretty much the same in the descriptives. I<br>
remember running stats on time-unresolved data before and getting a<br>
reasonable output, so I guess my ft_freqstatistics isn't working well<br>
right now. I just can't figure out why.<br>
Does anyone have any tips for how I could go about to find out why the<br>
negative clusters are being disregarded?<br>
<br>
Thanks a lot, Vit?ria<br></blockquote></div>-- <br><div><div><font face="arial, helvetica, sans-serif">Haiteng Jiang</font></div><div><font face="arial, helvetica, sans-serif">PhD candidate</font></div><div><font face="arial, helvetica, sans-serif">Neuronal Oscillations Group</font></div>
<div><font face="arial, helvetica, sans-serif">Donders Institute for Brain, Cognition and Behaviour</font></div><div><font face="arial, helvetica, sans-serif">Centre for Cognitive Neuroimaging</font></div><div><font face="arial, helvetica, sans-serif">Radboud University Nijmegen</font></div>
<div><span style="line-height:18px;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif"><br></font></span></div><div><span style="line-height:18px;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif">Visiting address</font></span></div>
<div><div style="text-align:left;background-color:rgb(255,255,255)"><div><span style="line-height:18px"><font face="arial, helvetica, sans-serif">Room 2.32</font></span></div><div><span style="line-height:18px"><font face="arial, helvetica, sans-serif">Donders Centre for Cognitive Neuroimaging</font></span></div>
<div><span style="line-height:18px"><font face="arial, helvetica, sans-serif">Kapittelweg 29</font></span></div><div><span style="line-height:18px"><font face="arial, helvetica, sans-serif">6525 EN Nijmegen</font></span></div>
<div><span style="line-height:18px"><font face="arial, helvetica, sans-serif">the Netherlands</font></span></div><div><span style="line-height:18px"><font face="arial, helvetica, sans-serif"><br></font></span></div></div>
</div><div><font face="arial, helvetica, sans-serif"> Tel.: +31 (0)243668291</font></div></div><div><font face="arial, helvetica, sans-serif"> Web: <a href="https://sites.google.com/site/haitengjiang/" target="_blank">https://sites.google.com/site/haitengjiang/</a></font></div>
</div></div></div>