A recent article by Gallagher et al. performs a conjunction analysis
involving the same contrast ("theory of mind" - "non-theory of mind") but
with 2 different modalities, cartoons vs. sentences. I have a similar
situation with data from 14 subjects and would like to do the same kind of
analysis and would appreciate some advice:
We have 4 conditions in a block design: positive emotion,
negative emotion, neutral emotion, and fixation (implicit baseline). There
are 2 runs of these conditions using word stimuli (i.e., negative words,
etc.), followed by 1 longer run of the same conditions using picture
stimuli. We've run separate random effects analyses on the word runs and
the picture runs so far, but are also interested in finding areas of
common activation across the modalities (word, picture) for each contrast.
For example, do negatively associated words activate some of the same
regions that negative pictures do? Based on the separate random effects
analyses there appear to be common areas of activation but we would like
to approach this issue more quantitatively.
Is conjunction analysis at the first level the way to go here, or perhaps
there is a second level analysis that can be used to address this
question, if I assume sphericity? If conjunction is appropriate, how
generally would one proceed?
Thanks,
--Stephan
Stephan Hamann, Ph.D.
Dept. of Psychology, Emory University
Atlanta, GA 30322
email: [log in to unmask]
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