There are two ways to do it:
1. You can use DOSS, making each subject it's own class. Then create one "Variable". For a given input, set the variable to either +1 or -1 depending upon whether it corresponds to the first or second time point. Then create a contrast as [0 0 0 0 ... 0 0 0 1], where there are as many 0s as subjects. The last "1" will correspond to the Time Point variable.
2. Alternatively, if you are using mris_preproc, you can specify "--paired-diff", then just use a one-sample group mean test. See the --help. This may be easier, and will also allow you to add a between subject factor.
doug
Fornito, Alexander wrote:
Hi, I'd like to run a simple repeated-measures analysis tetsing for change in thickness measures between 2 time points. There is no between-subjects factor, only the effect of time. Do I just set up a standard DOSS FSGD file, or do I use a different format? The tutorial only covers between-subjects designs. Thanks, Alex
Alex Fornito M.Psych/PhD (clin. neuro.) candidate Melbourne Neuropsychiatry Centre and Department of Psychology National Neuroscience Facility The University of Melbourne Levels 2 & 3, Alan Gilbert Building 161 Barry St Carlton South Vic 3053 Australia Ph: +61 3 8344 1624 Fax: +61 3 9348 0469 email: alexander.fornito@wh.org.au
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