Hi all,
I had a question about using the motion correction parameters as covariates
in specifying models. If my understanding is correct, the parameters
express relative spatial position and orientation in mm or radians from the
reference scan.
If this is true, to correct for motion-related artifacts, wouldn't it be
more appropriate to use the difference (delta) in each parameter from one
image to the next, as this would seem to be a better estimate of motion
(i.e. change in spatial position per unit time = velocity) at the the time
of each image?
Likewise, next taking the scan-to-scan differences of those differences
would estimate acceleration (i.e. change in velocity per unit time =
acceleration).
Is anyone out there doing this? Or, if my thinking on this is flawed, can
anyone help clarify this for me?
Thanks,
Rick
--------------------
Richard Yun, M.D.
Research Fellow
Yale University Department of Psychiatry
(203) 932-5711 ext 4530
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