Hello,
I am currently processing fMRI data that includes 2 sessions.
Can anyone provide more info or a reference regarding Martin's statement to "Be aware when choosing the constrast because youŽll have both sessions in your design matrix."?
For example, if I have 2 sessions and 3 conditions per session:
1: A B C
2: A B C
If I wanted to define the contrast A -B, would the contrast weights be:
1 -1 0 1 -1 0
or
0.5 -0.5 0 0.5 -0.5 0
Thanks!
-Julie
On Fri, May 4, 2012 at 5:09 AM, Martín Martínez
<[log in to unmask]> wrote:
No, you dont need to combine both sessions in spatial pre-processing. What you have to do is to pre-process each session and when performing the model specification, you indicate that you have two sessions. Be aware when choosing the constrast because youŽll have both sessions in your design matrix.
Martin.
2012/5/4 studyer
<[log in to unmask]>
Dear all,
I have two EPI sessions of one subject with same scanning parameters. And I want to combine the two sessions in the same first-level model. Do I need to combine the two sessions at first when doing the spatial processing jobs?
thanks,
John
--
Julie E. McEntee, MA, CCRP
Image Processing Technologist
Center for Neuroscience & Regenerative Medicine, NIH/USUHS
The Henry M. Jackson Foundation for the Advancement of Military Medicine
NIH Clinical Center
Building 10, Room 1C370
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