Hi Gang,
This thread has been useful but I have a few additional questions:
We are using 3dLME over 3dMVM because:
1. missing data
2. multiple random effects (e.g., site, family, sibling)
3. w/s repeated continuous measures (e.g., age at time 1 and time 2)
My questions are as follows:
1. How do you specify the random effect for multiple variables? Ignoring age (see question 2), would this be correct?
Rx effects: site (category 1-8), family_ID (continuous categorical), sib (factor)
Btwn subjects: group
W/n subject: time
Covariates: sex, handedness, IQ_PR, IQ_VC
3dLME -prefix filename -jobs 12 \
-model "group*time+sex+handedness+IQ_PR+IQ_VC+site+family_ID+sib" \
-qVars "sex,handedness,IQ_PR,IQ_VC" \
-ranEff "~1" \
-SS_type 3 \
-dataTable \
Subj group age time sex handedness IQ_PR IQ_VC site family_ID sib InputFile \
000000240546 case 14.48767123 BSL 0 1 131 140 4 143 0 EPI_stop_signal/con_0002_stop_success.nii.gz \
000000240546 case 19.63016545 FU2 0 1 131 140 4 143 0 EPI_stop_signal/con_0002_stop_success.nii.gz \
000000871047 case 14.44657534 BSL 1 1 112 117 2 147 1 EPI_stop_signal/con_0003_stop_success.nii.gz \
000000871047 case 18.5479721 FU2 1 1 112 117 2 147 1 EPI_stop_signal/con_0003_stop_success.nii.gz \
2. Age issue:
Age is both a within subject and between subject factor. Therefore, would this be correct?
3dLME -prefix filename -jobs 12 \
-model "group*time*age+age+sex+handedness+IQ_PR+IQ_VC+site+family_ID+sib" \
-qVars "age, sex,handedness,IQ_PR,IQ_VC" \
-ranEff "~1" \
-SS_type 3 \
-dataTable \
Subj group age time sex handedness IQ_PR IQ_VC site family_ID sib InputFile \
000000240546 case 14.48767123 BSL 0 1 131 140 4 143 0 EPI_stop_signal/con_0002_stop_success.nii.gz \
000000240546 case 19.63016545 FU2 0 1 131 140 4 143 0 EPI_stop_signal/con_0002_stop_success.nii.gz \
000000871047 case 14.44657534 BSL 1 1 112 117 2 147 1 EPI_stop_signal/con_0003_stop_success.nii.gz \
000000871047 case 18.5479721 FU2 1 1 112 117 2 147 1 EPI_stop_signal/con_0003_stop_success.nii.gz \
3. Also, since age is w/s and there is variance between interval between time 1 (BSL) and time 2 (FU2) do I need to estimate a random slope for age?
3dLME -prefix filename -jobs 12 \
-model "group*time*age+age+sex+handedness+IQ_PR+IQ_VC+site+family_ID+sib" \
-qVars "age,sex,handedness,IQ_PR,IQ_VC" \
-ranEff "~1+age" \
-SS_type 3 \
-dataTable \
