Dear FSLers,
In a first-level FEAT analysis I have the choice of breaking down one of
my tasks (it's a slow event related paradigm) into 2 different EV as
opposed to keeping all in 1 EV.
So, say I have 8 trials, which can be further grouped in 2 categories (4
trials each).
I envision 2 options (at a later point I'll be interested in looking at
differences between the two categories, but not for now):
a) create 1 EV file (with all 8 trials) and then create a contrast with
+1 in this EV only
b) create 2 EV files (with 4 trials each) and then create a contrast
with + 1 in both EVs
Would (a) and (b) yield the same results (I'm thinking esp of the
variance of estimation in the voxel-wise regression)?
cheers
martin
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“Well! I’ve often seen a cat without a grin,” thought Alice, “but a grin without a cat! It’s the most curious thing I ever saw in my life!” [Lewis Carroll, Alice in Wonderland]
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Martin M. Monti
Princeton University
Department of Psychology
Green Hall 3-S-8
(609) 258-5679
www.webmartin.net
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