Mixed-effect regression with repeated measures

Dear all,

I am trying to regress a continuous brain anatomy measure with a behavioral parameter while accounting for age and sex effect. The difficulty I am facing is that I have for each subject two anatomical measures, one for each hemisphere:

Subject    Anatomy measure    Hemisphere      Age     Sex    Behavior
1                1.2             1           22      2       16,2
1                1.5             2           22      2       16,2
2                1.7             1           25      1       19,3      
2                1.8             2           25      1       19,3
...

How can perform the regression anatomy*behavior while taking into account this repeated measure problem ? I thought that the appropriate way to do that was to perform a linear mixed-effect regression with subjects as a fixed factor. However I am not sure this is a good solution. Does anyone know a function that would deal with repeated measure design for linear regression ?

Thanks in advance !

Lucie

Answer 1

[Peng Li]

This is also an old post now. I guess what the author of this post meant to use subject as a random effect, not a fixed effect, so that the within subject correaltion would be properly taken care of. For me I think that's the way we do it.