Illuminated FSL masters,
I am following a patient longitudinally, on a series of different tasks.
Say the design is 1 subject performing 2 tasks each repeated 4 times.
Would this set-up be correct?
EV1: Overall subject mean [is this actually needed?]
EV2: Task1 mean
EV3: Task2 mean
EVs4-7: Task1_T0 (reference group), Task1_T1, Task1_T2, Task1_T3
EVs8-11: Task2_T0 (reference group), Task2_T1, Task2_T2, Task2_T3
(visually..)
Input File
[Task1 T0] 1 1 0 0 0 0 0 0 0 0 0
[Task1 T1] 1 1 0 0 1 0 0 0 0 0 0
[Task1 T2] 1 1 0 0 0 1 0 0 0 0 0
[Task1 T3] 1 1 0 0 0 0 1 0 0 0 0
[Task2 T0] 1 0 1 0 0 0 0 0 0 0 0
[Task2 T1] 1 0 1 0 0 0 0 0 1 0 0
[Task2 T2] 1 0 1 0 0 0 0 0 0 1 0
[Task2 T3] 1 0 1 0 0 0 0 0 0 0 1
Contrasts & F-tests would be as follows:
C1: 0 0 0 0 1 0 0 0 0 0 0 F1 (i.e. EV5)
C2: 0 0 0 0 0 1 0 0 0 0 0 F1 (i.e. EV6 )
C3: 0 0 0 0 0 0 1 0 0 0 0 F1 (i.e. EV7)
C4: 0 0 0 0 0 0 0 0 1 0 0 F2 (i.e. EV9)
C5: 0 0 0 0 0 0 0 0 0 1 0 F2 (i.e. EV10)
C6: 0 0 0 0 0 0 0 0 0 0 1 F2 (i.e. EV11)
Contrasts & Ftests interpretations:
F1 is the within subject effect for Test1
F2 is the within subject effect for Test2
Each contrasts is essentially like a Dunnett test (i.e. comparison of
each repetition to its reference group). However, without the actual
multiple comparisons correction of the Dunnett test (considering the
number of voxels tested a few multiple comparisons are maybe not that
big of an issue?!).
Does this sound about right?
cheers
martin
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