Karl Friston wrote:
>
> Dear Thomas,
>
> > > Use 'mean and exponential decay'. This is an equivalent formulation
in
> > > terms of within-epoch adaptation' suggesting the earlier responses
> > > supervene over later responses. Furthermore these two basis functions
> > > allow more easily interpretable contrasts.
> > >
> > > With best wishes - Karl
> >
> > Dear Karl,
> >
> > If I got this right, this model allows to remove the effects of
> > within-epoch adaption. In my case I am interested in the effects of
> > adaption, so in the SPM96 model I would have looked at the late
> > responses. How can this be done using the 'mean and exp. decay' model
>
> Simply define a contrast testing for the decay term with a '1' for
> the appropriate [second] basis function associated with the trial[s]
> of interest and '0' elsewhere.
>
> With best wishes - Karl
Dear Karl,
this shows the areas with decreasing singal strength during stimulation. Can
I
use -1 for the second basis function of each trial to look at areas that
have an increasing signal during the Stim epoch ?
Thank you
Thomas Stephan
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Thomas Stephan Email: [log in to unmask]
Klinikum Grosshadern
Neurologisches Forschungshaus
Marchioninistr. 23 Fon: +49 089 / 7095-4819 *NEU*
81377 Muenchen Fax: +49 089 / 7095-4801
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