I usually use quadratic. I would not worry too much about trying to extract out every last drop of efficiency. Things are going to change enough when you actually analyze the data. What you want to do is just avoid having really bad sequences.
doug Leo Fernandino wrote: > Hi there, > > I noticed that when I include additional polynomials as nuisance variables, > the efficiency of the design decreases. When should we include polynomials to > account for scanner drift, and how do we decide the maximum order of the > polynomials? Does it depend only on the length of the run? My runs are 8 min > each, am I justified in having a quadratic polynomial? > > Thank you, > > Leo Fernandino > > > > > ------------------- > Leonardo Fernandino, Ph.D. > Post-Doctoral Scholar > Human Neuroscience Laboratory > Department of Neurology > The University of Chicago > 5841 S. Maryland Ave. MC-2030 > Chicago, IL 60637 > Phone: (773)-834-7847 > http://www.fmri.uchicago.edu/ > > "Those who cannot remember the past are condemned to repeat it." - George > Santayana > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
