Dear Forum,
In trying to understand the results out put for a 2x2x2 MEEG ANOVA. I fail
to understand how the number of voxels is derived. Data was acquired at 1KHz
no filtering, downsampled to 600 Hz, epochs of 676 samples (200 ms baseline)
were filtered with a 1.5 Hz high-pass. The data was then baseline corrected
and scanned for artifacts using peak-to-peak algorithm with an amplitude
threshold of 3.5 pT, the data was averaged and converted to images by
interpolating to 64x64 image size. Images were smoothed using a (6,6,5)
kernel. We assume that the number of voxels in the results (see attached
PDF) is derived by 64x64x676?
Application of FWE or a conservative P value (<0.01) results in nothing, and
thresholding 0.01<p<0.05 results in everything significant. Any advise to
find a sensible middle ground in the results would be appreciated. We plan
to use a (6,6,7) kernel. But to improve the situation is it advisable to
reduce the number of corrections by smoothing to a smaller image, or using a
smaller epoch size?
Thanks
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