<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Dear Katia,<div class=""><br class=""></div><div class="">I would mention that the statistics were corrected for multiple comparisons using the cluster methods. You may report the p-value for stats and the actual difference in terms of values between the conditions for effect size.</div><div class=""><br class=""></div><div class="">Best,</div><div class=""><br class=""></div><div class="">Arno<br class=""><div class="">
<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; 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="">Arnaud Delorme, PhD<br class="">Centre de Recherche Cerveau et Cognition - UMR 5549<br class="">Pavillon Baudot, Hopital Purpan, BP 25202<br class="">31052 Toulouse Cedex 3, France</div>
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<br class=""><div><blockquote type="cite" class=""><div class="">On Nov 15, 2015, at 7:39 PM, Kaelasha Tyler <<a href="mailto:ktyler@swin.edu.au" class="">ktyler@swin.edu.au</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="font-size: 10pt; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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; direction: ltr; font-family: Tahoma;" class="">Thanks Steve,<div class=""><br class=""></div><div class="">Very clear.</div><div class="">K.<br class=""><div class=""><br class=""><div style="font-family: Tahoma; font-size: 13px;" class=""><div style="font-family: 'Times New Roman'; font-size: 16px;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class="">PhD Candidate</span></div></div><div style="font-family: 'Times New Roman'; font-size: 16px;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class="">Brain and Psychological Sciences Research Centre</span></div></div><div style="font-family: 'Times New Roman'; font-size: 16px;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class="">Swinburne University of Technology</span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class="">Melbourne</span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class="">Australia</span></div></div></div></div><div style="font-family: 'Times New Roman'; font-size: 16px;" class=""><hr tabindex="-1" class=""><div id="divRpF617917" style="direction: ltr;" class=""><font face="Tahoma" size="2" class=""><b class="">From:</b><span class="Apple-converted-space"> </span><a href="mailto:fieldtrip-bounces@science.ru.nl" class="">fieldtrip-bounces@science.ru.nl</a><span class="Apple-converted-space"> </span>[<a href="mailto:fieldtrip-bounces@science.ru.nl" class="">fieldtrip-bounces@science.ru.nl</a>] on behalf of Stephen Politzer-Ahles [<a href="mailto:stephen.politzer-ahles@ling-phil.ox.ac.uk" class="">stephen.politzer-ahles@ling-phil.ox.ac.uk</a>]<br class=""><b class="">Sent:</b><span class="Apple-converted-space"> </span>Sunday, 15 November 2015 10:15 PM<br class=""><b class="">To:</b><span class="Apple-converted-space"> </span><a href="mailto:fieldtrip@science.ru.nl" class="">fieldtrip@science.ru.nl</a><br class=""><b class="">Subject:</b><span class="Apple-converted-space"> </span>Re: [FieldTrip] statistical reporting cluster based permutation<br class=""></font><br class=""></div><div class=""></div><div class=""><div dir="ltr" class=""><div class=""><div class=""><div class=""><div class=""><div class="">Hello Kaelasha,<br class=""><br class=""></div>There isn't really any one absolute right way to report these; my best suggestion is to look in the literature for other papers in your area that have reported cluster based stats, and see how they do it. In my experience it's usually sufficient to report the p-value, polarity, and approximate spatiotemporal distribution of an effect (e.g., "there was a significant positive effect (p=.042) based on a cluster of fronto-central electrodes lasting from x ms to y ms..."), as is done in this paper:<a href="https://www.researchgate.net/publication/38112722_Reasoning_with_Exceptions_An_Event-related_Brain_Potentials_Study" target="_blank" class="">https://www.researchgate.net/publication/38112722_Reasoning_with_Exceptions_An_Event-related_Brain_Potentials_Study</a>.<br class=""></div>I also find raster plots to be a nice way to visualize the spatiotemporal extent of a cluster; see, e.g., this paper:<a href="http://joshuakhartshorne.org/papers/HartshorneSnedekerLiemAzarKim.pdf" target="_blank" class="">http://joshuakhartshorne.org/papers/HartshorneSnedekerLiemAzarKim.pdf</a><br class=""><br class=""></div>See also<span class="Apple-converted-space"> </span><a href="http://www.fieldtriptoolbox.org/faq/how_not_to_interpret_results_from_a_cluster-based_permutation_test" target="_blank" class="">http://www.fieldtriptoolbox.org/faq/how_not_to_interpret_results_from_a_cluster-based_permutation_test</a><span class="Apple-converted-space"> </span>for some suggestions about wording and interpretation of the effects.<br class=""><br class=""></div>Best,<br class=""></div>Steve<br class=""><div class=""><div class=""><div class=""><div class=""><div class=""><div class=""><div class="gmail_extra"><br clear="all" class=""><div class=""><div class="gmail_signature"><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><span class=""><div class=""><br class=""><br class="">---<br class=""></div>Stephen Politzer-Ahles<br class="">University of Oxford<br class="">Language and Brain Lab, Faculty of Linguistics, Phonetics & Philology<br class=""><a href="http://users.ox.ac.uk/~cpgl0080/" target="_blank" class="">http://users.ox.ac.uk/~cpgl0080/</a></span></div></div></div></div></div>Message: 1<br class=""><div class="gmail_quote"><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; border-left-width: 1px; border-left-style: solid; border-left-color: rgb(204, 204, 204); padding-left: 1ex;">Date: Sun, 15 Nov 2015 01:07:30 +0000<br class="">From: Kaelasha Tyler <<a href="mailto:ktyler@swin.edu.au" target="_blank" class="">ktyler@swin.edu.au</a>><br class="">To: "<a href="mailto:fieldtrip@science.ru.nl" target="_blank" class="">fieldtrip@science.ru.nl</a>" <<a href="mailto:fieldtrip@science.ru.nl" target="_blank" class="">fieldtrip@science.ru.nl</a>><br class="">Subject: [FieldTrip] statistical reporting cluster based permutation<br class=""> tests<br class="">Message-ID:<br class=""> <<a href="mailto:FB8747C478C3AF489C8F5164C02011B9E48CAE50@gsp-ex01.ds.swin.edu.au" target="_blank" class="">FB8747C478C3AF489C8F5164C02011B9E48CAE50@gsp-ex01.ds.swin.edu.au</a>><br class="">Content-Type: text/plain; charset="iso-8859-1"<br class=""><br class="">Hi all,<br class=""><br class="">I am writing up results for cluster based permutation tests that I ran on masked priming meg data.<br class=""><br class="">I have to admit I am not entirely sure the exact form for reporting the stats on these.<br class=""><br class="">For example, when comparing two conditions, with n=20, I have one significant positive cluster over left frontal and parietal areas. The stats for this cluster read:<br class=""><br class="">prob: 0.0420<br class="">clusterstat: 1.2443e+04<br class="">stddev: 0.0063<br class="">cirange: 0.0124<br class=""><br class="">Has anyone else completed and rerooted on results, having used cluster based permutation tests?<br class="">Mean values don't seem to be appropriate here, so would it simply be the p value and standard deviation for the significant clusters that would be reported on?<br class=""><br class="">Thanks,<br class="">K<br class=""><br class="">PhD Candidate<br class="">Brain and Psychological Sciences Research Centre<br class="">Swinburne University of Technology<br class="">Melbourne<br class="">Australia<br class=""><br class=""><br class=""></blockquote></div><br class=""></div></div></div></div></div></div></div></div></div></div></div></div><span style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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; float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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;" class=""><span style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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; float: none; display: inline !important;" class="">fieldtrip mailing list</span><br style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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;" class=""><a href="mailto:fieldtrip@donders.ru.nl" style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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;" class="">fieldtrip@donders.ru.nl</a><br style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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;" class=""><a href="http://mailman.science.ru.nl/mailman/listinfo/fieldtrip" style="font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 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;" class="">http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a></div></blockquote></div><br class=""></div></body></html>