Hi,
On 20 Feb 2007, at 02:44, pengxu wei wrote:
> Dear all,
>
> In a paper (Vince D. Calhoun, T¨šlay Adali, Lars Kai Hansen, Jan
> Larsen, James J. Pekar. ICA of Functional MRI Data: An Overview.
> Fourth International Symposium on Independent Component Analysis
> and Blind Source Separation. 2003.281-288), it is said
> (because of both SICA and TICA have their own limits) ' In
> general it is recommended to
> explore the full spectrum of independency and perform both SICA
> and TICA'
> so we can get thorough results.
>
> After several years, now has Melodic, as a TICA method and with
> many revised versions, solved such limits such as ' the on/off
> structure of the
> activation time course doesn't match well with the sparse source
> assumption of the Bell-Sejnowski approach' so we don't need a
> additional SICA?
MELODIC is spatial ICA ("SICA") not temporal, because FMRI data are
not well-suited to TICA - primarily because you don't have enough
timepoints to generate an accurate temporal PDF.
I can't think of any reason why you would particularly want to run
temporal-ICA on FMRI data as opposed to spatial-ICA.
Cheers, Steve.
>
> Best regards,
>
> wei
>
>
>
> Finding fabulous fares is fun.
> Let Yahoo! FareChase search your favorite travel sites to find
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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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