Table 5. Change in fMRI Stroop Effect.

SUD: substance use disorder patient group; HC: healthy control group; BA: Brodmann’s area; p_FWE: family-wise-error-corrected p-value; k: cluster size in voxels; R: right; L: left. Peak coordinates are the MNI coordinates (x, y, z) of the peak voxel within each cluster.

1. Within group changes in the ‘Stroop effect’ (incongruent vs. congruent trials) across sessions were assessed with paired t-tests and a threshold of voxel-level p<0.005 with conjoint cluster-level p_corrected<0.05.
2. Group differences in change scores were assessed with a two sample t-test in SPM2 comparing change in BOLD signal activity following treatment (or re-test) masked for regions engaged by the SUD group at pre or post-treatment to a threshold of voxel-level p<0.005 and conjoint cluster extent of k=19.

Cluster Description	k	T	Peak coordinates
			x	y	z
I. Within-Group Change in ‘Stroop Effect’ Related Regional BOLD Signal Following Treatment
i. SUD Post-treatment < SUD Pre-treatment
R/L midbrain/ lentiform nucleus/ thalamus/ cerebellum/ brainstem/ subthalamic nucleus	176	8.35	8	−12	−4
L middle and superior temporal gyrus/ BA 37	65	6.30	−52	−36	−8
R inferior frontal gyrus/ caudate/ middle temporal gyrus/ BA 10, 13, 46, 47	206	6.02	48	36	8
R cuneus/ BA 18, 30, 31	70	5.96	20	−80	16
R anterior cingulate gyrus/ dorsolateral PFC/ BA 9, 32	54	5.87	8	36	24
R middle frontal gyrus/ BA 8, 9	60	5.23	52	12	36
R superior frontal gyrus/ BA 6, 8	62	4.74	0	8	68
ii. HC Session 2 < HC Session 1
L lentiform nucleus/ putamen/ lateral globus pallidus	70	5.21	−24	12	8
II. Group Difference in Change in ‘Stroop Effect’ Related Regional BOLD Signal Following Treatment
i. SUD(Post-Treatment vs. Pre-Treatment) < HC(Session2 vs. Session 1)
R lateral globus pallidus/ lentiform nucleus/ midbrain/ subthalamic nucleus	21	4.05	8	−12	−4