Hello,

I am new to FSL and I would appreciate any help with the following.

I have 21 subjects, each with 2 runs. It’s a repeated measures design with 2 factors, each at 2 levels. One factor is manipulated between runs (i.e. level 1 and 2 in two separate runs), and the other within each run. I have analyzed each run separately at the first level and defined contrasts of interest.

I have then run 21 separate 2nd level analyses (one for each subject) with fixed effects. I have selected the option “lower level FEAT directories” and uploaded the two first level directories for each subject.
1) My first question is whether this is correct, or I should instead choose lower level cope images, and what would be the difference in terms of 3rd level analysis.
2) My second question is for the 3rd level analysis. I want to run a repeated measures ANOVA looking at main effects and interaction between the 2 factors.
I am not sure how to adapt the 1-factor 4-levels (Rep Meas) ANOVA described on the FSL website (http://www.fmrib.ox.ac.uk/fsl/feat5/detail.html#ANOVA1factor4levelsRepeatedMeasures) to my design (in terms of Inputs and EVs), particularly for the factor between runs.

Any basic suggestions will be much appreciated.
Thanks very much
Chiara

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Chiara Sambo, PhD
King's College London

Centre for Neuroimaging Sciences
Box 089, Institute of Psychiatry
De Crespigny Park
London SE5 8AF
Tel: 0203 228 3042