cluster-based analysis question

[Eric Maris]

Dear Bornali,




This is more of a statistical methods question.  I'm interested in doing
test-retest evaluation in a data set and, most specifically, formally
assessing my intuition that there are stable individual differences in the
ERSP associated with performing a certain task, such that the overall
"pattern" of one subject's ERSP is highly replicable, and thus reliably
different from the ERSPs of other subjects. Is the fieldtrip cluster-based
permutation test  a suitable procedure for implementing this test?  Has
anyone done this type of analysis already?  Any advice would be appreciated.



Yes, it is straightforward to do this type of analysis in Fieldtrip. This is
a so-called between-trials analysis. Your independent variable is SUBJECT,
with levels the different subjects in your study. You can do this analysis
for every pair of subjects (using statfun=indepsamplesT) or for all subjects
jointly (using statfun=indepsamplesF).

You will be testing the null hypothesis that there are no differences
between subjects (or, in reliability terminology, that there are no reliable
individual differences). This is a strict null hypothesis. However, it will
definitely be of interest to see where the individual differences are most
pronounced; on which regions of the scalp, on which time points relative to
some stimulus, and in which frequency bands.

Good luck,

Eric Maris



dr. Eric Maris
Donders Institute for Brain, Cognition and Behavior

Center for Cognition and F.C. Donders Center for Cognitive Neuroimaging

Radboud University
P.O. Box 9104
6500 HE Nijmegen
The Netherlands
T:+31 24 3612651
Mobile: 06 39584581

F:+31 24 3616066
E: e. <mailto:e.maris at donders.ru.nl> maris at donders.ru.nl

















Thanks so much,

Bornali


--
Medical Scientist Training Program
Neuroscience Training Program
University of Wisconsin - Madison
Health Emotions Research Institute
 <mailto:bkundu at wisc.edu> bkundu at wisc.edu

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The aim of this list is to facilitate the discussion between users of the
FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and
EEG analysis.

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http://www.ru.nl/fcdonders/fieldtrip/


----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/neuroimaging/fieldtrip.
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