1 Mar
2010
1 Mar
'10
12:24 p.m.
Hi all,
I've covaried age in a group difference analyses on cortical thickness data both in qdec for vertex-based and in spss for the gyral-based data. For the vertex-based data, covarying age has almost no effect, and if anything intensifies the group differences. However, when run in qdec, covarying age in this dataset wipes out almost any group differences. Is covarying in qdec to be trusted? It seems strange to me that these two methods would result in such extreme differences in results. Thanks,
Nathan