Dear All:
We are doing a fMRI study with N-back stimuli (0back, 1 back, 2 back and 3
back). The test design is as follows:
It is a block design. Each stimuli (e.g. 1 back) were presented to the
subject 14 times continuosely, then anothe stimuli (e.g. 3 back) were
presented to the subject for 14 times. We have 4 different testing scripts
(A, B, C, D). In each script the sequence of 0 back, 1 back, 2 back, and 3
back are randomly arranged. For each subject had 4 functional scannings on
the same day. After the first 2 functional scanning, the subjects were
removed from the scanner and allowed 10 minutes break. Then, the subjects we
put back in the scanner and had another 2 functional scanning. We randomly
picked the testing script during each functional scanning.
My question is should I treat the 4 functional scanning for 1 subject as 1
subject with 4 sessions, or 2 subjects with 2 sessions for each subject or
just treat the 4 functional runs of each subject as 4 subjects?
Thanks a lot.
Jiansong Xu
UCLA Braing Mapping Center
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