Hi Wei Wen
There are indeed issues with these slow task frequencies, you should have
a look at the two papers mentioned bellow before you start your
experiments. Maybe you should go for true perfusion measurements.
Best
Torben
A. M. Smith, B. K. Lewis, U. E. Ruttimann, F. Q. Ye, T. M. Sinnwell, Y.
Yang, J. H. Duyn, and J. A. Frank. Investigation of low frequency drift in
fMRI signal. NeuroImage, 9:526–33, 5 1999.
J. Wang, G. K. Aguirre, D. Y. Kimberg, A. C. Roc, L. Li, and J. A. Detre.
Arterial spin labeling perfusion fMRI with very low task frequency. Magn
Reson Med, 49:796–802, 5 2003.
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> Hi,
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> Are there any issues there if we have a very long epoch block design?
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> We are planning to have a meditation fMRI study in which the meditator is
> doing a meditation in the scanner for 6 minutes (meditation condition) and
> plus several minutes of non-meditation. The signal drifting, the low
> frequency, etc. What do you people think? Any studies (reports, papers)
> similar to this that you know of please?
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> Many thanks and regards,
>
>
> Wei Wen
>
> UNSW, Australia
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> .
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