[pymvpa] [PyMVPA] hevay head movements
Yaroslav Halchenko
debian at onerussian.com
Fri Aug 22 01:40:50 UTC 2014
On Tue, 19 Aug 2014, cfygj wrote:
> I want to conduct MVPA, and I have four runs data. Now I need to fslmerge
> these four runs and make a common mask for them. The problem that I need
> to address is that heavy head movements between these runs. That is to
> say, each run has samll head movements, however, heavy head
> movements would generate when fslmerge these 4 runs. How to remove the
> possible effect of head motion on BOLD signal. Anyone have the quick
> answer on this?
you just motion correct all of your BOLD runs (after fslmerge, do not
motion correct before at all) to a sample image taken from one of
your runs (at times, closest to the anatomical, i.e. from the last run
if anatomical is taken after). Some people do it multi-pass even: after
initial pass of motion correction take the mean of all motion corrected
volumes from all runs as you target image and motion correct original 4
runs to that one.
hope this helps
--
Yaroslav O. Halchenko, Ph.D.
http://neuro.debian.net http://www.pymvpa.org http://www.fail2ban.org
Research Scientist, Psychological and Brain Sciences Dept.
Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755
Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419
WWW: http://www.linkedin.com/in/yarik
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