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
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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Eryilmaz, H. Hamdi