SPM users:
We are in need of help.
We have recently conducted a longitudinal fMRI study in which we
collected three time points. There was an uneven number of participants
per time point, such that we went from 35 to 25 to 12 subjects (which
means we have 12 subjects that came back for all 3 sessions, but
several others attrited).
We have two questions:
1) Is there an analysis technique that we can use to compare activation
using all of the subjects (including the attrited ones)? Currently we
have analyzed the data with just the 12 subjects using paired t-tests
between the time points.
2) More importantly, we are interested in correlating individual
differences measures with activation across time. For instance, we
collected Stroop data. We want to see how the correlations with their
Stroop performance changed over time, including all subjects and not
just the 12 that came back all three time points.
Any advice here will be greatly appreciated. Thanks.
Sharlene
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