Testing Loss and Gain of Statistical Power

Surface quality can be tested by tracking change in statistical power between groupstats results of the ADNI60 and Buckner40 subject sets. The test diff_power, currently located in utils/test/diff_power, computes differences in significance and locates surfaces regions with the largest change. Given a source and reference groupstats test (i.e. thickness of controls vs ADs in dev and stable6), diff_power does the following:

  1. Subtracts the ref sig.mgh from the src sig.mgh (producing sigdiff.mgh) and masks any vertices that did not gain or lose significance (default threshold: p=0.05)
  2. Computes clusters of change in significance and locates the peak sigdiff.mgh vertex for each cluster