Table 2. Stroop-Related Neural Activity in Cannabis-Dependent and Healthy-Comparison Individuals: Group Differences and Relationship to Treatment.

		Peak coordinates				Statistics
Regions of activation	Laterality	x	y	z	Cluster size	Maximum	Mean
Group differences in Stroop-related neural activity at pretreatment baselinea:
Healthy comparisons > cannabis dependent						t	t
Ventral Striatum/dorsal striatum/midbrain/subthalamic nucleus/thalamus/amygdala/parahippocampal gyrus	R+L	−12	−12	−9	674	−4.56	−2.45
Dorsolateral prefrontal cortex/middle frontal gyrus	L	−54	15	39	164	−4.01	−2.59
Dorsal prefrontal cortex/superior frontal gyrus	R	24	45	33	147	−4.33	−2.69
Anterior insula/superior temporal gyrus	R	27	24	0	116	−3.59	−2.46
Superior and middle temporal gyrus	R	57	−51	15	113	−3.30	−2.41
Amygdala/parahippocampal gyrus	R	30	0	−27	96	−5.08	−2.71
Dorsolateral prefrontal cortex precentral gyrus/middle frontal gyrus	R	54	6	36	90	−3.92	−2.66
Correlations between pretreatment Stroop-effect related neural activity and cannabis-abstinence measures:
Conjunction of pretreatment Stroop-related neural activity correlation with three within-treatment cannabis-abstinence measuresb						r	r
Occipital/lingual gyrus	L	−29	−66	1	69	0.59	0.49
Posterior cingulate cortex	L	−29	−70	16	59	0.67	0.52
Occipital/Lingual Gyrus	R	33	−52	−9	51	0.67	0.50
Dorsal anterior cingulate cortex	R	3	3	38	22	0.59	0.49
Cuneus	L	−10	−74	16	21	0.61	0.50
Supramarginal gyrus	R	61	−49	36	20	0.55	0.49
Pretreatment Stroop-related neural activity correlation with % days cannabis abstinence during 1-year follow-upc
Positive correlations						r	r
Posterior cingulate/superior cerebellum	L	−3	−66	9	178	0.79	0.54
Occipital/fusiform gyrus	L	−24	−90	−15	120	0.78	0.57
Occipital/fusiform gyrus	R	42	−78	0	119	0.73	0.55
Ventral striatum/perigenual/subgenual anterior cingulate	L	−6	30	12	119	0.82	0.55
Superior temporal/lateral orbitofrontal/inferior frontal gyrus	L	−39	18	−21	99	0.81	0.57
Occipital/fusiform/lingual gyrus/cerebellum	L	−24	−51	−15	94	0.83	0.55
Negative correlations
Anterior insula/putamen /inferior frontal gyrus/caudate	L	−21	18	−3	127	−0.76	−0.56

Stroop-related neural activity was computed as incongruent >congruent trials. Peak coordinates are reported in Montreal Neurological Institute (MNI) space (x, y, z). Cluster size is in 3 × 3 × 3 mm voxels.

^at-tests were computed to assess group differences between cannabis-dependent (N=20) and healthy comparison (N=20) individuals. Results are whole-brain family-wise-error (FWE) corrected for multiple comparisons at p<0.05.

^bConjunction analysis of three within-treatment cannabis-abstinence measures that were correlated with pretreatment Stroop-related neural activity in the cannabis-dependent group only (N=20): (1) percent cannabis-negative urines, (2) percent self-reported cannabis-abstinent days during treatment, and (3) maximum self-reported consecutive days of abstinence (Table 1 for group means). All correlations were preformed robustly. Joint conjunction threshold is p<0.000125, with a cluster threshold of 20 voxels.

^cA whole-brain robust correlation was computed to identify regions where Stroop-related neural activity was associated with long-term treatment outcome, as measured by percent of days of self-reported abstinence at 1-year follow-up. Results are family-wise-error (FWE) corrected for multiple comparisons at p<0.05. Cannabis-dependent individuals with follow-up data available only, N=18.