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Dear Lee,

If you're running an ROI analysis you'll have quite a bit of flexibility in your modeling options as you can use repeated measures ANOVA or regression tools from standard statistics software.  I would look into the repeated measures modeling approaches available in your favorite statistics software package.  You'd extract the 8 values for each subject and enter them into the analysis as indicated by the software.

Hope that helps,
Jeanette

On Wed, Nov 5, 2014 at 10:00 AM, Lee Harrison <[log in to unmask]> wrote:
Hello,

I'm trying to analyse a 2x2x2 RM group design but am struggling when it comes to my ROI analysis.

In terms of the design I have:

factor A(scan 1 and scan 2)
factor B (low and high pain)
factor C (easy and hard task)

For each subject I have four experimental cope files (for each scan, so 8 in total):
Cope 1 - Easy_low (scan 1)
Cope 2- Easy_high (scan 1)
Cope 3- Hard_low (scan 1)
Cope 4 - Hard_high (scan 1)

Cope 1 - Easy_low (scan 2)
Cope 2 - Easy_high (scan 2)
Cope 3 - Hard_low (scan 2)
Cope 4 - Hard_high (scan 2)

Ideally I would like to assess whether there are any main effects (A,B,C) or interactions (2- and 3-way) for each of my pre-defined ROIs. I can see a lot of hurdles due to the RM design. Would it be the case that I use fslmaths to create bias scores representing the main effects and interactions and use t-tests to explore the differences?

Any advice would be much appreciated.

L