[FieldTrip] permutation test: multiple comparison correction for the p-values

[Steinmann, Iris]

Hi everybody,

I' m using the 'ft_freqstatistics' function to find significant differences between two time-frequency spectra
(see the used options down below).
While fieldtrip calculates the permutation test it throws the following information:

"performing FDR correction for multiple comparisons
the returned probabilities are uncorrected, the thresholded mask is corrected"

Since I'm using the p-values for the following analysis and not the thresholded mask, I was wondering how I
get my p-values corrected for multiple comparison?

Does anyone has an idea? Thanks in advance!


I used the following options:

cfg = [];
cfg.channel     = 'all';
cfg.latency     = [2.3 2.8];
cfg.avgoverchan = 'yes';
cfg.avgovertime = 'no';
cfg.frequency = [9 14];
cfg.parameter   = 'powspctrm';
cfg.alpha = 0.05;
cfg.tail = 0;
cfg.correctm = 'fdr';
cfg.correcttail = 'prob';
cfg.ivar = 1;
cfg.statistic = 'ft_statfun_indepsamplesT';
cfg.method = 'montecarlo';
cfg.design = design; % defined in at the beginning of the function
cfg.numrandomization = 1000;

stat_TF = ft_freqstatistics(cfg, TF_remove, TF_noremove)
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