Dear SPM community,
would you please help clarify a question regarding the different tests. For simplicity, let's
assume a simple block design with a task and a control condition.
Is my interpretation that the F-test assigning 1 "one" to the task and 0 "zero" to all
control variables (such as motion regressors) addresses the question whether there is
either activation or deactivation compared to baseline correct?
How do I take this question to a second level analysis? The F- test produces no ".con"
images which are being used for a second level analysis as "scans".
Of course, one could perform two separate t-tests assigning 1 "one" to the task and, as a
separate test, assigning -1 "minus one" to the task. Would these two t-tests address the
questions: Is there activation (1 contrast) / deactivation (-1 contrast) compared to
The two t-tests described would produce two ".con" images. Could they somehow be used
for a second level F-test analysis?
I appreciate your feedback,
University of Alabama