Dear spm-experts,
I have conducted a prospective f-mri study and want to analyze the data
according to the two stage repeated measures ANOVA with partitioned errors
as described in Henson & Penny 2003.
The design:
n-back working memory task with an active and a control condition (2-back &
0-back)
2 measuring time points (t1 & t2)
2 groups of participants (a & b)
I want to analyze the data by means of a 2(task condition) x 2 (measuring
timepoint) x 2 (groups) repeated measures ANOVA. Therefore on the first level
I will have to compute the contrasts for (correct me if I’m wrong):
1. Main effect of task (2-back vs 0-back)
2. Measuring time point (t1 vs t2)
3. Interaction task and measuring time point
My question:
How to compute these first level contrasts?
For the main effect of task I have computed the t-contrasts 2-back – 1-back
for each participant and each time point – is this correct?
Do I have to compute T or F contrasts?
How are the contrasts for the measuring time points and the interactions
computed?
Thanks in advance & regards
Ben
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