within subjects partitioning

[Eric Maris]

Hi Josh,


>   I'm using timelockstatistics to perform a within subjects cluster based
non-
> parametric test.  I have two conditions and ten subjects.  The data from
each
> subject consists of a spatial array of 160 electrodes at one time point.
>   My question is how are the data randomly partitioned. Are all samples
across
> subjects and conditions put into one group and 20 random drawings (10
> subjects, 2 conditions) of 160 electrodes performed?  Or is data within
each
> subject preserved so that there are 10 groups of 320 electrodes from each
of
> which two partitions are made?


In a within-subjects design with two conditions, the permutation is
performed as follows: the two spatio-spectral-temporal (possibly with empty
spectral and temporal dimensions) data matrices (one for every condition)
per subject are randomly permuted WITHIN every subject. This is also
described in Maris & Oostenveld (JNM, 2007).


Good luck,

Eric Maris




>   Thanks so much,
>   Josh
>
> ----------------------------------
> 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/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/fcdonders/fieldtrip.