I have data from 23 subjects on a task that has 6 different stimuli which represent a
combination of two factors (probability and expected value). There are three levels of the
probability factor and 2 levels of the expected value factor, resulting in the 6 stimuli. I am
interested in conducting an ANOVA that would give me neural activity related to probability
alone, expected value alone, and the interaction of the two. I am having trouble figuring
how to do this- the examples in the FSL manual seem straightforward except I am unsure
what the inputs are (copes from first level, I presume?) and they only use factors with 2
levels so i am not sure how to make a similar model with 3 levels.
Based on the FSL manual and previous posts, I thought I would need to create a design file
with 23x6 inputs (copes for each stimulus type from individual feats). Then, each EV was a
level of the first and second factors (resulting in 5 EVs). Once I did this, I realized that I
didn't know how to create the interaction term. I have attached the design file that I
started for 8 of the subjects.
Any help with this would be greatly appreciated!
Amy Roy, Ph.D.
NYU Child Study Center
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