Table 6.

Post hoc analyses examining the source of interaction effects between diagnostic group and past substance abuse.

Region	BA	x	y	z	Activity pattern
					CON (no past SA) vs. SCZ (no past SA)		CON (no past SA) vs. SCZ (with and without past SA)
					n-Back version A	n-Back version B	n-Back version A	n-Back version B
L superior frontal gyrus	8	0	29	53	C < S***	C < S***	C < S+**	C < S+***
L DLPFC	9	−40	31	27	C = S	C = S	C = S+	C = S+
L middle frontal gyrus	6	−35	10	54	C < S**	C < S*	C = S+	C = S+
L fusiform gyrus	19	−49	−72	−10	C < S**	C < S*	C < S+**	C = S+
L insula	13	−40	9	−3	C < S**	C < S**	C < S+**	C < S+**
L insula	13	−41	−7	5	C < S*	C < S*	C < S+**	C < S+***
L ant./mid. cingulate	24	0	−6	36	C < S**	C < S***	C < S+***	C < S+***
L thalamus	−	−9	−28	−4	C < S***	C < S*	C < S+**	C < S+*
R middle frontal gyrus	10	36	55	3	C < S**	C < S***	C < S+**	C < S+*
R middle frontal gyrus	6	36	8	58	C < S**	C < S*	C = S+	C = S+
R orbitofrontal gyrus	47	41	18	−2	C < S*	C < S**	C = S+	C < S+**
R precentral gyrus	44	53	13	8	C < S*	C < S*	C < S+*	C < S+***
R inferior parietal lobule	40	41	−53	54	C < S*	C < S*	C = S+	C = S+

Results are from two-sample t-tests. Coordinates (x, y, z) reflect Talairach template space (57). “ =,” represents no significant difference; BA, Brodmann area; L, left; R, right; DLPFC, dorsolateral prefrontal cortex; ant., anterior; mid., middle; C, control participants without past substance abuse; S, schizophrenia patients without past substance abuse; S+, combined schizophrenia patients with and without past substance abuse; *p < 0.05, **p < 0.01, ***p < 0.001.