Hello,
I'm sorry to bother everyone but I wanted to check what I am doing is
correct.
I would like to investigate between-group differences in activations. We
have two groups (patient and control), and we want to localise the
face-specific voxels in both groups and then look at the effect of stimulus
manipulation (direct or averted eye gaze) on these regions. The problem is
that one group's face selective areas may be more variable (spatially). This
is why we need an ROI approach, we don't care where the face specific bits
are, we just care about their response to direct and averted eye gaze.
I used a localiser scan to select my ROIs for each subject. I then use
MarsBaR to give me a contrast value for a contrast in my main task (i.e.
direct - averted eye gaze). I plan to then enter all these contrast values
into SPSS and do a simple 2-sample t-test to see if the groups are
significantly different.
Is this the right way to do it and am I right in thinking I will find which
group has the greatest difference between direct and averted gaze in their
face specific areas?
If so, what more would I gain by getting % signal change for each subject,
what more would it tell me?
Thanks for any help you can give,.
Geoff
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