If you are using the Different Offset Different Slope (DODS) model, then, by default, it tests at age=0. If you want to test at age=8, just subtract 8 from all the ages
On 09/26/2017 01:57 PM, Eryilmaz, H. Hamdi wrote:
Dear all,
We are modeling changes in cortical thickness over time using a cross-sectional design. We have two groups of participants, age 8 to 18. In the cortical regions that interest us, there is generally a linear decline in thickness with age. Each group can be fitted to a best-fit line. The question we are interested in is whether there is a significant difference in thickness between groups *at a given age *(i.e., not just collapsed across age) — specifically, at the earliest age point (age=8). Is this possible to model across the brain surface in Freesurfer?
Thanks, Hamdi and Josh
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