cluster statistic on one sample

[Eric Maris]

Dear Floris,



> I have a question about statistical analysis on the sensor level.
> I would like to make use of the cluster size thresholding of the
> clusterrand routine in Fieldtrip. Unfortunately, in the current
> wrapper, it seems there is no option for a one-sample T-test? There is
> an activation-baseline test, and a (in)dependent samples test between
> two conditions, but what I want to do is simply test whether a 14
> (subjects) x 275 (channels) matrix is different from zero, taking into
> account the spatial relations between adjacent sensors. (The data
> points are regression weights from a multiple-regression analysis, so
> there's no easy way to split it into two parts.)
> I assume this should be easy to tweak, but I couldn't come up with any
> smart ideas how to do it.
> Anyone any ideas?

I'm afraid that I have to disappoint you, Floris. Your null hypothesis is a
typical parametric null hypothesis; the expected value of some
(matrix-valued) variable being equal to zero. The null hypothesis that is
tested by a nonparametric permutation test is equality across experimental
conditions of the probability distribution from which the
(condition-specific) data are drawn. Since you have single condition only, I
see no way of applying the theory behind nonparametric permutation testing
(of the type described by Maris & Oostenveld, 2007) to your data.

To solve your problem we need a brilliant theoretical insight.


Greetings,

Eric






>
> Thanks in advance!
>
> Floris
>
> ----------------------------------
> 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.