<div dir="ltr"><div><div><div><div><div>Hello Kaelasha,<br><br></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">https://www.researchgate.net/publication/38112722_Reasoning_with_Exceptions_An_Event-related_Brain_Potentials_Study</a>.<br></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">http://joshuakhartshorne.org/papers/HartshorneSnedekerLiemAzarKim.pdf</a><br><br></div>See also <a href="http://www.fieldtriptoolbox.org/faq/how_not_to_interpret_results_from_a_cluster-based_permutation_test">http://www.fieldtriptoolbox.org/faq/how_not_to_interpret_results_from_a_cluster-based_permutation_test</a> for some suggestions about wording and interpretation of the effects.<br><br></div>Best,<br></div>Steve<br><div><div><div><div><div><div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><span><div><br><br>---<br></div>Stephen Politzer-Ahles<br>University of Oxford<br>Language and Brain Lab, Faculty of Linguistics, Phonetics & Philology<br><a href="http://users.ox.ac.uk/~cpgl0080/" target="_blank">http://users.ox.ac.uk/~cpgl0080/</a></span></div></div></div></div></div>Message: 1<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Date: Sun, 15 Nov 2015 01:07:30 +0000<br>
From: Kaelasha Tyler <<a href="mailto:ktyler@swin.edu.au">ktyler@swin.edu.au</a>><br>
To: "<a href="mailto:fieldtrip@science.ru.nl">fieldtrip@science.ru.nl</a>" <<a href="mailto:fieldtrip@science.ru.nl">fieldtrip@science.ru.nl</a>><br>
Subject: [FieldTrip] statistical reporting cluster based permutation<br>
tests<br>
Message-ID:<br>
<<a href="mailto:FB8747C478C3AF489C8F5164C02011B9E48CAE50@gsp-ex01.ds.swin.edu.au">FB8747C478C3AF489C8F5164C02011B9E48CAE50@gsp-ex01.ds.swin.edu.au</a>><br>
Content-Type: text/plain; charset="iso-8859-1"<br>
<br>
Hi all,<br>
<br>
I am writing up results for cluster based permutation tests that I ran on masked priming meg data.<br>
<br>
I have to admit I am not entirely sure the exact form for reporting the stats on these.<br>
<br>
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>
<br>
prob: 0.0420<br>
clusterstat: 1.2443e+04<br>
stddev: 0.0063<br>
cirange: 0.0124<br>
<br>
Has anyone else completed and rerooted on results, having used cluster based permutation tests?<br>
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>
<br>
Thanks,<br>
K<br>
<br>
PhD Candidate<br>
Brain and Psychological Sciences Research Centre<br>
Swinburne University of Technology<br>
Melbourne<br>
Australia<br>
<br><br></blockquote></div><br></div></div></div></div></div></div></div></div>