coherence normalization

Tom Holroyd tomh at KURAGE.NIMH.NIH.GOV
Fri Oct 22 17:15:49 CEST 2004

On Thu, 21 Oct 2004, Robert Oostenveld wrote:

> The dominating effect of the refdip is indeed very problematic.
> ... Better test and map the significance of the difference in
> coherence between two conditions using randomization of the
> trials before the coherence is beamed ...

Yes.  What I finally did was to export the coherence volumes to
AFNI, and run an ANOVA (four conditions by eight subjects; it
took 24 hours for Matlab to calculate the volumes at 1 cm
resolution, and I don't even have as many trials as I would
like).  The means across conditions of course show the refdip
source but the contrasts in the ANOVA (which are basically
subtractions) nicely cancelled them out, leaving cool-looking
effects.  :-)

Now, how can I extract the phase?  Is that stored somehere?

Dr. Tom Holroyd
"A man of genius makes no mistakes. His errors are volitional and
are the portals of discovery." -- James Joyce

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