LLN, le 17/02/05
Dear SPM users,
This is a repost of a previous message. As I got no answer, I give it
a second try. Any idea?
Any help and comment appreciated... Thanks in advance,
Mauro.
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I'd be happy to have any advice on the following issue.
I ran a block-design fMRI adaptation experiment with 5 conditions +
fixation. We are looking for adaptation - i.e., decrease of the bold
signal - accross conditions, but we have no apriori on the form of
this decrease (linear, etc.). I computed the contrasts of interest
for each subject, and took the con_files in a RFX analysis. In order
to find areas where activation are, say, A>B>C, I used the following
2-level contrast (1-way Anova within subject):
[(A-fix)-(B-fix)] masked inclusive by [(B-fix)-C-fix)]
I feel that this is not the easiest/best way to do what I want, but
cannot figure out a better way. Using a contrat such as [1 0 -1] is
not really an alternative as it boils down to A-C.
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Mauro PESENTI
Research Associate, National Fund for Scientific Research (Belgium)
Unite de Neurosciences Cognitives
Departement de Psychologie
Universite Catholique de Louvain
Place Cardinal Mercier, 10
B-1348 Louvain-la-Neuve
tel.: +32 (0)10 47 88 22
fax: +32 (0)10 47 37 74
E-mail: [log in to unmask]
http://www.nesc.ucl.ac.be
http://www.nesc.ucl.ac.be/mp/pesentiHomepage.htm
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