Hi all,

I'm experiencing troubles while analyzing connectivity data from gPPI with 3dLME. I ihave a fixed effect (emotion) and a random effect (reaction time).
I get in output a main effect for emotion, the random effect (that should be the correlation between connectivity and reaction time), and the interaction.

Now the trouble.
After thresholding and visualizing results, I extracted values of connectivity from clusters affected by the main effect and the reaction time (with 3dROIstats). But, in some cases, I DO NOT see correlations at all between reaction time and connectivity extracted from those clusters! I still can't understand why I see the effect only in the model and not after extraction. I was wondering if this can be due to using a small mask (~2000 voxel).
Any ideas?

[ I considered only values of alpha < 0.05 ]

thanks in advance,
Simone

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here is the model, if it may be useful

3dLME \
-prefix LME_out \
-jobs 4 \
-model "condition*react" \
-mask mask_TN+tlrc \
-qVars "react" \
-qVarCenters '0' \
-ranEff '~1*react' \
-SS_type 3 \
-num_glt 7 \
-gltLabel 1 'neutral' -gltCode 1 'condition : 1*neutral' \
-gltLabel 2 'negative' -gltCode 2 'condition : 1*negative' \
-gltLabel 3 'neutral-negative' -gltCode 3 'condition : 1*neutral -1*negative' \ <---main effect
-gltLabel 4 'neu-RT' -gltCode 4 'condition : 1*neutral react :' \
-gltLabel 5 'negRT' -gltCode 5 'condition : 1*negative react :' \
-gltLabel 6 'Interaction' -gltCode 6 'condition : 1*neutral -1*negative react :' \ <---interaction
-gltLabel 7 'correlationRT' -gltCode 7 'react' \ <---correlation
-dataTable \
Subj react condition InputFile \
s1 75.1017 neutral ../../subjF1/bucket_ppi+tlrc'[4]' \
s2 -47.3512 neutral ../../subjF2/bucket_ppi+tlrc'[4]' \
.
.
s17 85.9628 neutral ../../subjF17/bucket_ppi+tlrc'[4]' \
s1 17.2099 negative ../../subjF1/bucket_ppi+tlrc'[6]' \
s2 -53.1114 negative ../../subjF2/bucket_ppi+tlrc'[6]' \
.
.
s17 107.1490 negative ../../subjF17/bucket_ppi+tlrc'[6]'

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