While it is similar to that derived empirically by Zarahn and colleagues,
I think the HRF used in SPM was actually derived by Karl Friston from
a PCA across activated voxels (activation as determined by a Fourier set)
from the data described in Josephs et al. (1997), but apologies to anyone
concerned if my historical understanding is wrong.
"Johnson, Sterling - MHA" wrote:
> I believe the shape of the HRF was empirically derived based on the work of
> Zarahn
>
> Zarahn, E., G. Aguirre, and M. D'Esposito, A trial-based experimental design
> for fMRI. Neuroimage, 1997. 6(2): p. 122-38.
>
> Best wishes,
>
> Sterling C. Johnson, Ph.D.
> Neuropsychology
> Barrow Neurological Institute
> 222 W. Thomas Rd. Ste 315
> Phoenix AZ 85013
> ph: 602-406-3671
> fx: 602-406-6115
> email [log in to unmask]
>
> > -----Original Message-----
> > From: Dr Afraim Haddadi [mailto:[log in to unmask]]
> > Sent: Wednesday, February 07, 2001 11:39 AM
> > To: [log in to unmask]
> > Subject: SPM HRF Reference
> >
> >
> > Dear all,
> >
> > Can anyone provide me with a literature reference for
> > the default canonical HRF shape, assumed by spm_hrf?
> >
> > Much appreciated,
> >
> > Afraim
> >
> >
> > ----------
> > Dr A Salek-Haddadi
> > Clinical Research Fellow
> > Institute of Neurology
> >
--
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DR R HENSON
Institute of Cognitive Neuroscience &
Wellcome Department of Cognitive Neurology
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