A follow-up on the question below. If one condition is prevalent
(present during 70-80% of the scan time) while the other condition is
rare (present only during the remaining 20-30% of the scan time), are
SPM results comparing the two conditions still valid?
Thank you.
Manbir Singh
> Hi all,
>
> I just need to know if the regressors entered in the design matrix
>have to be orthogonal to one another? Are the SPM results still
>meaningful if some of the regressors are not orthogonal to others?
>How does nonorthogonality affect the results?
>
>Thank you
>
>Todd Penney
--
Manbir Singh Ph.D.
Professor of Radiology and Biomedical Engineering
Founding Director: Biomedical Imaging and Telemedicine Program
Director: ADRC Neuroimaging Core
University of Southern California
Denney Research Building, DRB-163, 1042 Downey Way
University Park, Los Angeles, CA 90089-1111
Tel. 213 740-0837, FAX 213 821-3897
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