Dear AFNI experts,

I followed the procedure of gPPI (see the link below) to do connectivity analysis for an block-design fMRI experiment.
[afni.nimh.nih.gov]
Below is my script:
3dDetrend -polort 1 -prefix ${connf}/${roi}/${1}.${roi}.Seed_dtr.1D ${connf}/${roi}/${1}.${roi}.sSeed.1D\'
1dtranspose ${connf}/${roi}/${1}.${roi}.Seed_dtr.1D ${connf}/${roi}/${1}.${roi}.Seed_dtr_t.1D

waver -dt 2 -GAM -inline 1@1 > ${connf}/${roi}/GammaHR.1D
3dTfitter -RHS ${connf}/${roi}/${1}.${roi}.Seed_dtr_t.1D -FALTUNG ${connf}/${roi}/GammaHR.1D ${connf}/${roi}/${1}.${roi}.Seed_dtr_t_Neur.1D 012 0

1deval -a ${connf}/${roi}/${1}.${roi}.Seed_dtr_t_Neur.1D\' -/new_vis_reg.txt -expr "a*b" > ${connf}/${roi}/${1}.visualReg.1D
1deval -a ${connf}/${roi}/${1}.${roi}.Seed_dtr_t_Neur.1D\' -b /new_aud_reg.txt -expr "a*b" > ${connf}/${roi}/${1}.audioReg.1D

waver -GAM -peak 1 -TR 2 -input ${connf}/${roi}/${1}.visualReg.1D -numout 360 > ${connf}/${roi}/${1}.visualReg_gm.1D
waver -GAM -peak 1 -TR 2 -input ${connf}/${roi}/${1}.audioReg.1D -numout 360 > ${connf}/${roi}/${1}.audioReg_gm.1D

3dDeconvolve -input pb03.$subj.r*.blur+orig.HEAD \
-censor censor*.1D \
-polort A \
-local_times \
-num_stimts 11 \
-stim_times_AM1 1 c2_visual.txt 'dmBLOCK(0)' \
-stim_label 1 Vis \
-stim_times_AM1 2 c1_auditory.txt 'dmBLOCK(0)' \
-stim_label 2 Aud \
-stim_file 3 motion_demean.1D'[0]' -stim_base 3 -stim_label 3 roll \
-stim_file 4 motion_demean.1D'[1]' -stim_base 4 -stim_label 4 pitch \
-stim_file 5 motion_demean.1D'[2]' -stim_base 5 -stim_label 5 yaw \
-stim_file 6 motion_demean.1D'[3]' -stim_base 6 -stim_label 6 dS \
-stim_file 7 motion_demean.1D'[4]' -stim_base 7 -stim_label 7 dL \
-stim_file 8 motion_demean.1D'[5]' -stim_base 8 -stim_label 8 dP \
-stim_file 9 ${1}.${roi}.Seed_dtr_t.1D -stim_label 9 ${roi}_ts \
-stim_file 10 ${1}.visualReg_gm.1D -stim_label 10 ${roi}*Vis \
-stim_file 11 ${1}.audioReg_gm.1D -stim_label 11 ${roi}*Aud \


The effect of interest was the connectivity between one seed ROI and the whole head under two experimental conditons (see the stim_files 10 and 11).
Surprisingly, the connectivity was almost all negative across the whole head except that the seed ROI positively correlated with itself.
I wonder whether anyone encounters the same situation and would love to know why it is the case. Thank you.

Sincerely,
Veda