My study involves 3 runs per subject -- I wanted to do Rand FX so I started
by creating a multi-session (3 runs) fixed effect design for each subject --
there are 4 trial types which repeat in a counterbalance order across runs
---
MY QUESTION IS .....
WHEN DEFINING THE CONTRAST (LETS SAY ALL-REST SO: 1 1 1 1) DO I NEED TO
REPEAT THE FOUR ONES TWO MORE TIMES FOR ADDITIONAL RUNS OR DOES THE PROGRAM
AUTOMATICALLY ASSUME THAT'S WHAT I WANT ----
SO DO I PUT
1 1 1 1
(THE DESING MATRIX GRAPHICALLY REPRESENTS EACH RUN/SESSION - BUT IF I ONLY
PUT 4 'ONES' AND SUBMIT -- THE CONTRAST SEEM TO ONLY APPLY TO THE FIRST
SESSION???)
SO SHOULD I INSTEAD DO IT THIS WAY?
1 1 1 1 1 1 1 1 1 1 1 1
NOTE: I TRIED IT BOTH WAYS - MY DEGREES ARE FREEDOM END UP THE SAME - BUT I
GET A LOT MORE SIGNAL WITH THE 12 'ONES' ---
??????
THANKS IN ADVANCE FOR ANY HELP IN CLEARING THIS UP --- SIGI
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