Dear Jeff ,
> Does anyone have a function to measure either within or
> across cycle habituation in an anxiety experiemnt (ie. a
> region such as the amygdala)?
You should try the time x condition interaction in SPM2. It is under
"parametric modulation". Order denotes whether you only want to include a
linear term (order = 1) or higher order terms like quadratic (order = 2).
Across session habituation can easily be modelled using contrasts. However,
if you want to look at within and between session habituation AND an
interaction of the two, you need to go to more complex models as were
described in
Fletcher P, Büchel C, Josephs O, Friston K, Dolan R. Learning-related
neuronal responses in prefrontal cortex studied with functional
neuroimaging. Cereb Cortex 1999; 9: 168-78.
where we used such an approach in a learning experiment.
-Christian
Dr. Christian Büchel
Neurologische Universitätsklinik, Haus S10, Universitäts-Krankenhaus
Eppendorf
Martinistr. 52, D-20246 Hamburg, Germany
Tel.: +49-40-42803-4726 Fax.: +49-40-42803-9955
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www.uke.uni-hamburg.de/kliniken/neurologie/pages/mitarbeiter/buechel_c.htm
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