Freqstatistics plv

[Julian Keil]

Dear Fieldtrippers,

I have a question regarding the use of freqstatistics and phase
locking values:
Is it possible to use freqstatistics to compare phase-locking values?
If not, is there any other option to compare plv between conditions

I use the following code:

cfg=[];
cfg.statistic='depsamplesT';
cfg.method='analytic';
cfg.parameter='plvspctrm';
cfg.channel={'all'};  % 5 channels -> 10 channelcmb
cfg.tail=0;
cfg.alpha=0.05;
cfg.ivar=2;
cfg.uvar=1;
cfg.frequency   = [10 50];

cfg.design=[1:12,1:12;ones(1,12),ones(1,12)*2];

[stats_fus_vi]=freqstatistics(cfg,plv_fu{:},plv_vi{:});

I get the information:
renaming parameter 'plvspctrm' into 'powspctrm'
selected 5 channels
selected 201 time bins
selected 21 frequency bins

As I don't get any error message, I assume this works fine so far but
I'm confused about what is computed here: Is "powspctrm" used instead
of "plvspctrm" (i.e. the test is computed between power estimates
instead of phase locking values)? Why are only 5 channels selected
instead of the 10 combinations?

I already tried renaming "plvspctrm" and "labelcmb" to "powspctrm" and
"label" but then I get an error message, as freqstatistics selects 20
channels.

Thanks a lot for any advise

Julian


Dipl. Psych. Julian Keil

OBOB-Lab
University of Konstanz
Department of Psychology
P.O. Box D25
78457 Konstanz
Germany

Tel: ++49 - (0)7531 - 88 42 50
Fax: ++49 - (0)7531 - 88 28 91
Email: julian.keil at uni-konstanz.de
Homepage: http://www.uni-konstanz.de/obob








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