<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
Hi Sebastian,
<div class=""><br class="">
</div>
<div class="">ft_freqstatistics averages the power across the frequency bins, that have their bin-centre within the range specified by cfg.frequency.</div>
<div class=""><br class="">
</div>
<div class="">The output frequency in stat.freq represents the average of the bin-centres that went into the computation.</div>
<div class=""><br class="">
</div>
<div class="">No re-estimation of the power at this frequency is done.</div>
<div class=""><br class="">
</div>
<div class="">Best wishes,</div>
<div class=""><br class="">
</div>
<div class="">Jan-Mathijs</div>
<div class=""><br class="">
</div>
<div class="">
<div class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
J.M.Schoffelen, MD PhD<br class="">
Senior Researcher, VIDI-fellow - PI, language in interaction<br class="">
Telephone: +31-24-3614793</div>
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
Physical location: room 00.028</div>
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
Donders Centre for Cognitive Neuroimaging, Nijmegen, The Netherlands<br class="">
<br class="">
<br class="">
</div>
</div>
</div>
</div>
</div>
<div class="">
<div>
<blockquote type="cite" class="">
<div class="">On 19 Jul 2018, at 09:01, Sebastian Sauppe <<a href="mailto:sauppe.s@gmail.com" class="">sauppe.s@gmail.com</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">
Dear FieldTrip list,
<div class=""><br class="">
</div>
<div class="">I am testing different frequency bands with cluster-based permutation tests using ft_freqstatistics. For this, I use
<i class="">cfg.avgoverfreq = ‚yes‘</i> when setting up the test. However, I am unsure about how FieldTrip actually handles the frequency averaging. Does it take the mean power of the specified frequencies or does it take the power of the mean frequency?</div>
<div class=""><br class="">
</div>
<div class="">This is the relevant code I use:</div>
<div class=""><br class="">
</div>
<div class="">
<div style="margin: 0px; font-stretch: normal; font-size: 10px; line-height: normal; font-family: Courier;" class="">
...</div>
<div style="margin: 0px; font-stretch: normal; font-size: 10px; line-height: normal; font-family: Courier;" class="">
cfg.frequency = [3 8];</div>
</div>
<div class="">
<div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" size="1" class="">cfg.avgoverfreq =
</font><span style="font-family: Courier; font-size: 10px; color: rgb(178, 69, 243);" class="">'yes</span><font color="#b245f3" face="Courier" size="1" class=""><span style="caret-color: rgb(178, 69, 243);" class="">‘</span></font><font face="Courier" size="1" class="">;</font></div>
</div>
<div style="margin: 0px; font-stretch: normal; font-size: 10px; line-height: normal; font-family: Courier;" class="">
...</div>
<div style="margin: 0px; font-stretch: normal; font-size: 10px; line-height: normal; font-family: Courier;" class="">
<br class="">
</div>
<div style="margin: 0px; font-stretch: normal; font-size: 10px; line-height: normal; font-family: Courier;" class="">
<div style="margin: 0px; font-stretch: normal; line-height: normal;" class="">[stat] = ft_freqstatistics(cfg, data_A, data_B);</div>
<div class=""><br class="">
</div>
</div>
<div class="">In my data, I have the following frequencies: [3.9062 4.8828 6.1035 7.0801 8.0566 9.0332 10.0098]. In the statistics output, after averaging over frequencies stat.freq returns only 6.0059. This is the mean of the frequencies between 3 and 8. But
I can’t see whether somehow the power of that frequency was assessed in the test or whether the power of all frequencies in that band was first averaged and then tested.</div>
<div class=""><br class="">
</div>
<div class="">Regards,</div>
<div class="">Sebastian</div>
<div class="">
<div class="">
<div dir="auto" style="letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space;" class="">
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<br class="Apple-interchange-newline">
-----------</div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
Dr. Sebastian Sauppe</div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
Department of Comparative Linguistics, University of Zurich</div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
Homepage: <a href="https://sites.google.com/site/sauppes/" class="">https://sites.google.com/site/sauppes/</a></div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
Twitter: <a href="https://twitter.com/SebastianSauppe" class="">@SebastianSauppe</a></div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
Google Scholar Citations: <a href="https://scholar.google.de/citations?user=wEtciKQAAAAJ" class="">https://scholar.google.de/citations?user=wEtciKQAAAAJ</a> </div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
ResearchGate: <a href="http://www.researchgate.net/profile/Sebastian_Sauppe" class="">http://www.researchgate.net/profile/Sebastian_Sauppe</a></div>
<div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
ORCID ID: <a href="http://orcid.org/0000-0001-8670-8197" class="">http://orcid.org/0000-0001-8670-8197</a></div>
</div>
</div>
<br class="">
</div>
</div>
_______________________________________________<br class="">
fieldtrip mailing list<br class="">
<a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip" class="">https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br class="">
https://doi.org/10.1371/journal.pcbi.1002202<br class="">
</div>
</blockquote>
</div>
<br class="">
</div>
<br class="">
<br class="">
<div class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
<br class="">
</div>
</div>
</div>
</div>
</body>
</html>