Hi,
I am trying to test for statistical difference of activation in bilateral
task. I have simple boxcar paradigm, which gives nice activations in the both
L and R hemispheres and I would like to know which one is statistically
higher. I do the following:
1. flip slice-wise the whole time series so the AP orientation stays the same,
just L->R
2. merge in time the original and the flipped time series
3.setup the FEAT with EV1 and EV2, where the EV1 stops after 180s (the actual
length of the the original time series) and the EV2 skips 180s.
3. set C1 [1, -1] and C2 [-1, 1], though the second one is probably not
necessary
The problem is that I don't get any difference even in the data, where the
analysis of the original time series is evidently asymmetric. I would
appreciate if anybody could give me a hint what could be wrong with this
approach.
Thanks a lot in advance,
Martin
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Senior Clinical Research Associate
MRI Unit of the Department of Radiology
Erasme Hospital
Lennik Street 808
B-1070 Brussels
BELGIUM
tel: +32-2-555-4325
fax: +32-3-555-3994
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