Hi. I wonder if I could get your thoughts on the design of the following
experiment.
We have a multi-session PET study where subjects learn a motor task on day
1. They are scanned on the learning task and a control task. They return
over a 4 week period and are repeatedly scanned on the same learning and
control tasks. While performance dramatically improves on the learning
task, there is no change in the control task performance.
A reasonable question to ask is what may be the difference between the
learning scans across the days, while keeping in mind that there may be
non-specific changes that take place from session to session. These
non-specific changes might be observed in the activation changes that take
place in the control task from session to session. So, for example, one
might look at the difference between the learning scans in day 1 and 2 (call
them L1 and L2), and ask if there are voxels there that do not show up in
the difference between the control scans between the same two days. This
would be: Voxels with significant change in L1-L2 that are not a part of
C1-C2. This sounds to me like something that I might be able to do with
masking, but I'm not sure. Any thoughts would be appreciated.
with my thanks,
---------------------------------------------------
Reza Shadmehr
http://www.bme.jhu.edu/~reza
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|