We've run an experiment with a stimulus applied to the right ear. We
now want to perform the same experiment but with the stimulus applied
to the left ear. What are the advantages/disadvantages of using the
same subjects over again and applying the new stimulus.
If we used the same subjects I would like to do a multi-subject,
multi-condition analysis. (Left ear stimulus - right ear stimulus)
If we found new subjects I would do a 2 study multi-condition analysis.
(Left ear stimulus - rest) - (right ear stimulus - rest)
Using the same subjects should give more degrees of freedom and (I believe)
will lead to slightly stronger z-scores. But is this really better
than increasing the population size? There would be the same number of scans
in either case.
Many thanks.
dave
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