Table 2.

Brain activity for ‘planning versus baseline’ and ‘task load’ contrasts

Contrast	Anatomical location	Side	BA	Discordant (n = 38)				Concordant (n = 98)
				MNI coordinates			Z-score	MNI coordinates			Z-score
				x	y	z		x	y	z
‘Planning versus baseline’	Parietal cortex	L	7	−6	−66	51	Inf	−9	−60	51	Inf
		R	7	9	−69	57	7.30	3	−60	51	Inf
		L	40	−60	−36	36	5.36	−63	−33	36	4.72
		R	40	42	−42	42	6.54	45	−42	48	6.97
	Frontal cortex	L	6	−30	0	51	7.10	−21	9	57	Inf
		R	6	27	9	57	7.11	21	12	54	7.34
		L	8	−30	15	48	5.40	−30	15	48	6.26
		R	8	33	12	51	5.80	21	12	54	7.34
		L	10	−42	48	−6	5.29
		R	10	30	60	−3	4.60
		L	9/46	−48	24	36	5.55	−48	33	27	5.00
		R	9/46	45	30	36	5.97	45	27	24	4.38
	Occipital cortex	L	18					−33	−69	0	5.14
		R	18					21	−99	3	4.45
	Anterior cingulate	L	32	−6	21	48	5.41	−9	21	45	3.95
		R	32	9	21	48	4.46
	Caudate nucleus	L	–	−12	15	−3	6.25	−12	15	−3	Inf
		R	–	12	9	0	5.81	15	18	−3	7.02
	Thalamus pulvinar	L	–	−15	−30	12	2.72	−9	−30	6	3.03
		R	–	9	−27	12	4.07	3	−21	12	4.27
‘Task load’	Parietal cortex	L	7	−3	−69	51	6.04	−9	−72	60	Inf
		R	7	6	−66	63	5.35	12	−66	66	Inf
		L	40	−45	−60	48	6.05	−42	−57	48	7.24
		R	40	57	−54	42	5.52	54	−54	45	7.60
	Frontal cortex	L	6	−27	3	63	6.95	−27	12	60	Inf
		R	6	36	9	57	6.81	30	6	60	Inf
		L	8	−30	15	48	5.52	−3	27	45	Inf
		R	8	33	14	51	5.62	21	15	51	Inf
		L	9	−42	27	33	6.24	−42	30	33	Inf
		R	9	45	30	33	5.61	45	33	33	Inf
		L	10	−33	60	12	6.51	−36	51	9	7.08
		R	10	33	60	6	6.21	33	54	3	Inf
		L	44	−51	9	12	3.53
		R	44					54	9	12	3.85
		L	47	−51	18	0	2.95	−48	15	0	3.94
		R	47	51	18	0	3.14	33	24	−6	3.70
	Temporal cortex	L	37	−57	−48	−12	3.37
	Anterior cingulate	L	32	−6	24	36	5.90	−6	24	39	6.52
		R	32	9	33	30	5.30	9	24	36	4.32
	Caudate nucleus	L	–	−15	12	12	5.65	−18	18	6	6.57
		R	–	18	21	6	4.87	18	18	6	6.71
	Globus pallidus	L	–	−12	3	0	3.41	−15	0	−3	5.03
		R	–					12	3	−3	2.31
	Thalamus pulvinar	L	–	−9	−24	12	2.62	−12	−27	15	2.66
		R	–	9	−27	12	4.14	9	−27	12	3.08

Brain regions showing significant functional MRI signal increase for the ‘planning versus baseline’ and ‘task load’ contrasts in the discordant and concordant twin groups. Anatomical location = activated brain region; L = left hemisphere; R = right hemisphere; BA = Brodmann area; MNI coordinates (mm) = location of voxel with largest effect size; Z-score: z-value of voxel with largest effect size; Inf = infinite.