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help > RE: Movement
Apr 6, 2015 01:04 AM | Alfonso Nieto-Castanon - Boston University
RE: Movement
Hi Mary,
Yes, I also try to avoid if at all possible removing "whole-subject" data. In general I would suggest using a conservative ART threshold to remove individual scans, and then perhaps define a minimal number of valid scans (or a minimal number of degrees of freedom) that each subject should have in order to determine whether you should still remove "whole-subject" data (e.g. remove any subject with less than 100 valid scans). This can work even for high-movement cases where the focus is in finding those previous "clean" segments of the data (and removing subjects only if you could not find any such segments in their timeseries).
Hope this helps
Alfonso
Originally posted by Mary Newsome:
Yes, I also try to avoid if at all possible removing "whole-subject" data. In general I would suggest using a conservative ART threshold to remove individual scans, and then perhaps define a minimal number of valid scans (or a minimal number of degrees of freedom) that each subject should have in order to determine whether you should still remove "whole-subject" data (e.g. remove any subject with less than 100 valid scans). This can work even for high-movement cases where the focus is in finding those previous "clean" segments of the data (and removing subjects only if you could not find any such segments in their timeseries).
Hope this helps
Alfonso
Originally posted by Mary Newsome:
Hi. Yes, we definitely appreciate ART!
However, I am in a similar situation where I have only a handful of subjects who completed both pre- and post scans following an intensive therapy. Normally we would exclude anyone who had more than 2mm translation and 3 degrees rotation (original voxel sizes are 4.25mm), but the number of subjects is precious few, and one of them has 8 degrees of rotation through the last 2/3 of the run. Is there any general recommended cut-off (for example, 8 degrees is probably extreme and the subject should be omitted)? Or would ART effectively remove the offending scans, and then the problem becomes one of limited power?
Thanks for any help, as always!
Best,
Mary
However, I am in a similar situation where I have only a handful of subjects who completed both pre- and post scans following an intensive therapy. Normally we would exclude anyone who had more than 2mm translation and 3 degrees rotation (original voxel sizes are 4.25mm), but the number of subjects is precious few, and one of them has 8 degrees of rotation through the last 2/3 of the run. Is there any general recommended cut-off (for example, 8 degrees is probably extreme and the subject should be omitted)? Or would ART effectively remove the offending scans, and then the problem becomes one of limited power?
Thanks for any help, as always!
Best,
Mary
Threaded View
| Title | Author | Date |
|---|---|---|
| Kaylah Curtis | Jul 23, 2014 | |
| Mary Newsome | Apr 2, 2015 | |
| Alfonso Nieto-Castanon | Apr 6, 2015 | |
| Alfonso Nieto-Castanon | Jul 29, 2014 | |
| Xiaozhen You | Mar 31, 2015 | |
| Fred Uquillas | Mar 31, 2015 | |
| Xiaozhen You | Apr 1, 2015 | |
| Fred Uquillas | Apr 1, 2015 | |
| Alfonso Nieto-Castanon | Apr 2, 2015 | |
| Xiaozhen You | Apr 2, 2015 | |
| Ekaterina Shcheglova | Mar 26, 2023 | |
| Fred Uquillas | Apr 24, 2015 | |
| Alfonso Nieto-Castanon | Apr 28, 2015 | |
| Fred Uquillas | May 6, 2015 | |
| Arkan A | May 6, 2015 | |
| Alfonso Nieto-Castanon | May 6, 2015 | |
| Arkan A | May 7, 2015 | |
| Alfonso Nieto-Castanon | May 8, 2015 | |
| Arkan A | May 8, 2015 | |
| Bradley Taber-Thomas | Sep 30, 2014 | |
| Alfonso Nieto-Castanon | Oct 1, 2014 | |
| Bradley Taber-Thomas | Oct 1, 2014 | |
| Alfonso Nieto-Castanon | Nov 19, 2014 | |
| Kaylah Curtis | Jul 29, 2014 | |
| Alfonso Nieto-Castanon | Jul 30, 2014 | |
| Alexander Drobyshevsky | Oct 21, 2014 | |
| Alfonso Nieto-Castanon | Nov 19, 2014 | |
| Kaylah Curtis | Jul 30, 2014 | |
| Aleksandra Herman | Oct 23, 2014 | |