[FieldTrip] Question of cluster based permutation test

[Eelke Spaak]

Dear Arti,

Yes, strictly speaking, you should correct for the four comparisons by
e.g. Bonferroni or Holm-Bonferroni correction in order to control the
family-wise error rate. Alternatively, depending on your design, you
could consider a one-way ANOVA with 5 levels, optionally followed by
post-hoc tests.

Best,
Eelke

On Fri, 1 Jan 2021 at 06:34, Arti Abhishek <mailtome.2113 at gmail.com> wrote:
>
> Dear fieldtrip community,
>
> I have a question on cluster based permutation tests where one condition is compared with multiple other conditions. My experiment is a MMN multi-deviant paradigm where I have 4 deviants and one standard. I want to compare each deviant with the standard using the cluster stats to check the presence of MMN. Do I have to apply any correction as the same standard condition is compared multiple times?  My script is below:
>
> cfg                             = [];
>
> cfg.channel                     = {'EEG'};
>
> cfg.spmversion                  = 'spm12';
>
> cfg.latency                     = [-100 600];
>
> cfg.method                      = 'montecarlo';
>
> cfg.statistic                   = 'depsamplesT';
>
> cfg.correctm                    = 'cluster';
>
> cfg.clusteralpha                = 0.05;
>
> cfg.clusterstatistic            = 'maxsum';
>
> cfg.minnbchan                   = 2;
>
> cfg.tail                        = 0;
>
> cfg.clustertail                 = 0;
>
> cfg.alpha                       = 0.025;
>
> cfg.numrandomization            = 5000;
>
> cfg_neighb.layout               = lay;
>
> cfg_neighb.method               = 'triangulation';
>
> cfg.neighbours                  = ft_prepare_neighbours(cfg_neighb);
>
> %cfg.neighbours                 = neighbours;
>
> cfg.uvar                        = 1;
>
> cfg.ivar                        = 2;
>
> cfg.design                      = [1:19 1:19; ones(1,19) 2*ones(1,19)];
>
> Stat_MMN1                       = ft_timelockstatistics(cfg,  All_Dev1{:},All_Std{:});
>
> Stat_MMN2                       = ft_timelockstatistics(cfg,  All_Dev2{:},All_Std{:});
>
> Stat_MMN3                       = ft_timelockstatistics(cfg,  All_Dev3{:},All_Std{:});
>
> Stat_MMN4                       = ft_timelockstatistics(cfg,  All_Dev4{:},All_Std{:});
>
>
> Kind regards,
> Arti
>
>
>
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> https://doi.org/10.1371/journal.pcbi.1002202