You can highpass at 100s in the GUI and not lose the RSN signals. You
could also lowpass to remove some of the power in the physioogical
signals but that's not necessarily the best way of helping ICA from
separating what's left from the RSNs so probably don't worry about
lowpass. Wrt spatial filtering, again I'm afaid there aren't any hard
rules - if your data is very good (e.g. good SNR, long timeseries)
you may get away without spatial smoothing, but you'll probably need
a little (e.g. 3mm).
It's easier to describe what the characteristics of RSNs are than
what the non-RSNs will look like, as the latter vary more. RSNs look
like plausible grey matter network maps and have the characteristic
FFT response seen in our various RSN papers (see Beckmann in Proc Roy
Soc or De Luca in NeuroImage).
Cheers, Steve.
On 10 Jul 2007, at 20:35, Christopher Bell wrote:
> I was looking through the examples of spatial maps on Christian's
> Little
> Shop of Horrors website
> http://users.fmrib.ox.ac.uk/~beckmann/homepage/academic/littleshop/
> toc.html
>
> to help in determining melodic artefacts. I was particularly
> interested in
> the one labeled "stimulus unrelated physiological signals." How
> would you
> determine such a component, (timecourse, FFT of timecourse, a
> priori anatomy
> /physiology knowledge)? Also, if anyone has recommendations for how
> best to
> set high-pass temporal filtering and low-pass temporal filtering for a
> resting state fmri experiment, I would appreciate advice. The total
> timecourse of the experiment is 360 seconds.
>
> Chris Bell
> University of Minnesota
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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