[FieldTrip] Permutation statistics
Hwee Ling Lee
hweeling.lee at gmail.com
Sun Mar 23 15:19:30 CET 2014
Thanks for the tip.
I'm trying to perform a within-trial analysis.
I've got two sets of data, before and after resting state EEG activity.
First set has 54 trials and second set has 51 trials. Hence, my cfg.design
= [ones(1, 105); ones(1,54), ones(1,51)*2].
I've set up the statistical analysis like this:
cfg = ;
cfg.layout = lay;
cfg.channel = 'all';
cfg.latency = 'all';
cfg.trials = 'all';
cfg.frequency = 'all';
cfg.avgovertime = 'no';
cfg.avgoverfreq = 'no';
cfg.avgoverchan = 'no';
cfg.parameter = 'powspctrm';
cfg.method = 'montecarlo';
cfg.statistic = 'depsamplesT';
cfg.numrandomization = 1000;
cfg.design = design;
cfg.uvar = 1;
cfg.ivar = 2;
[stat] = ft_freqstatistics(cfg, post_c200freq, pre_c200freq);
However, I got an error message:
Error using ft_statfun_depsamplesT (line 84)
Invalid specification of the design array.
Error in ft_statistics_montecarlo (line 285)
[statobs, cfg] = statfun(cfg, dat, design);
Error in ft_freqstatistics (line 323)
[stat, cfg] = statmethod(cfg, dat, cfg.design);
Can someone please tell me what parameters did I specify wrongly? Thanks.
On 21 March 2014 20:10, Vitória Piai <v.piai.research at gmail.com> wrote:
> Dear Hweeling,
> There is nothing inherent to the ft_freqstatistics function that makes it
> special for MEG, rather than for EEG data. If you've been using other
> FieldTrip functions, you probably have used cfg.channel before. These are
> the channels present in your EEG data.
> How you should set some of the other parameters depends only on your
> design, not on whether the data are from MEG or EEG.
> Maybe you can specify what is unclear to you when calling the function so
> that you can get appropriate help!
> Good luck, Vitoria
> On 3/21/2014 3:36 PM, Hwee Ling Lee wrote:
> Dear all,
> I've got EEG datasets for 64 channels, and I would like to perform
> permutation statistics on the power frequency analyses to compare the two
> conditions (before and after resting state periods).
> However, I'm not sure how to operationalise the statistical analyses
> since most of the examples on the website are for MEG datasets.
> I would appreciate very much if someone could help me on this! Thanks!
> fieldtrip mailing listfieldtrip at donders.ru.nlhttp://mailman.science.ru.nl/mailman/listinfo/fieldtrip
Dr. rer. nat. Lee, Hwee Ling
German Center for Neurodegenerative Diseases (DZNE) Bonn
Email 1: hwee-ling.lee<at>dzne.de
Email 2: hweeling.lee<at>gmail.com
Ernst-Robert-Curtius Strasse 12, 53117, Bonn, Germany
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