Christine Gruetzner christine.gruetzner at GOOGLEMAIL.COM
Fri Mar 20 10:47:17 CET 2009

Dear Fieldtrippers,

I have some trouble using 'timelockstatistics' for task vs baseline
comparisons (the code I'm using is pasted below).

In the output of timelockstatistics, I get only one (!) time sample (prob,
stat, mask: 266 (channels) x 1 (time)), even if I specify the parameter
cfg.latency (e.g. [0 0.2]). However, when I plot the statistics afterwards,
it is possible to plot the whole time window I specified in cfg.latency -
even though the topography seems to be the same for each time bin...

The steps I do before computing timelockstatistics are the following:
1) Compute timelockanalyis separately for the task (cfg.latency = [0.05
0.4]) and the baseline (cfg.latency = [-0.4 -0.5]) separately
2) Compute timelockgrandaverage for task and baseline
3) Use the code below to compute timelockstatistics

Can anybody help me with this issue?
I would be very glad about any suggestions on what is going wrong here!!


cfg = [];
cfg.grad = timelockUprightTask{1}.grad;
cfg.channel = {'MEG', '-MLP12', '-MRC14', '-MLT41', '-MRC25', '-MRP56',
'-MRT21', '-ML021', '-MRO44', '-MRT47'};
cfg.statistic = 'actvsblT';
cfg.clusterthreshold = 'parametric';
cfg.clusteralpha = 0.05;
cfg.alpha = 0.05;
cfg.makeclusters = 'yes';
cfg.minnbchan = 3;
cfg.parameter = 'individual';
cfg.clusterstatistic = 'maxsum';
cfg.onetwo = 'twosided';
cfg.method = 'montecarlo';
cfg.correctm = 'cluster';
cfg.numrandomization = 1000;
cfg.latency = [0 0.2];
nSubjects = length(filesUprightTask);
a = [1:nSubjects];
b = ones(1,nSubjects);
cfg.design = [a a; b (2*b)];
cfg.uvar = 1;
cfg.ivar = 2;
timelockstat =

Christine Gruetzner, geb.Tillmann
Max-Planck-Institut für Hirnforschung
Abt. Neurophysiologie
Deutschordenstr. 46
60528 Frankfurt am Main

Phone: +49 (0)69/6301-83225
E-Mail: tillmann at mpih-frankfurt.mpg.de

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.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20090320/4f55e41c/attachment-0001.html>

More information about the fieldtrip mailing list