[FieldTrip] filtering during artifact detection

Maximilien Chaumon maximilien.chaumon at gmail.com
Wed Oct 26 10:42:27 CEST 2016

Dear all,
when attempting to detect blinks automatically on a continuous recording
without EOGs, I use a few frontal sensors and ft_artifact_eog as follows:

        cfg                         = [];
        cfg.dataset                 = fullfile(rootdir,f{iD});
        cfg.layout                  = 'neuromag306mag.lay';
        cfg.trialdef.eventtype      = 'STI101';
        cfg.trialdef.eventvalue      = {255};
        cfg                          = ft_definetrial(cfg);

        cfg.trl                     = [cfg.trl(1,1) cfg.trl(end,2) 0];
        cfg.channel                 = 'megmag';
        cfg.continuous              = 'yes';
        data                        = ft_preprocessing(cfg);

        cfg.artfctdef.eog           = [];
        cfg.artfctdef.eog.channel   = eogchans;
        cfg.artfctdef.eog.trlpadding = 0;
        cfg.artfctdef.eog.interactive = 'yes';

        [cfg, artifact{iC,iD}]      = ft_artifact_eog(cfg,data);

This opens an interactive window in which the EOG signal is not BPfiltered,
and contains in particular slow drifts that make the threshold detection
pretty inefficient. I'm surprised because cfg.artfctdef is supposed to
bpfilter 1-15Hz the data, isn't it?

Is this normal?
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