Table 2.

Clusters of significantly greater brain activation during encoding of old word pairs versus fixation in non-demented older adults

Brain region of maximum intensity voxel (MIV)	Volume (mm3)	Coordinates of MIV	η2 for OLD–FIX
APOE ε4 group
Widespread (left inferior parietal lobule maximum)	379584	−42, −37, 48	0.74
APOE Non-ε4 group
Left superior parietal lobule	54016	−22, −61, 44	0.74
Left middle occipital gyrus	34240	−42, −65, −4	0.73
Right cuneus	31040	−30, 73, 28	0.72
Right inferior occipital gyrus	28224	38, −85, −4	0.72
Right putamen and lateral globus pallidus	6464	26, −13, 4	0.71
Left putamen and lateral globus pallidus	5184	−22, −9, 4	0.74
ε4 > Non-ε4
Right anterior cingulate	5504	22, 43, 8	0.50
Right lingual gyrus	2368	26, −57, 0	0.49
Right middle temporal/parahippocampal gyri	1856	50, −69, 24	0.52
Right middle frontal gyrus	1472	30, 31, 40	0.51
Right posterior cingulate/precuneus	1280	6, −61, 20	0.48
Right cerebellar tonsil	960	6, −45, −36	0.52

For the within-group analysis, ε4 subjects displayed widely diffuse and bilateral whole brain activation which met criteria for a single cluster (see Fig. 1), while non-ε4 subjects showed smaller significant clusters (note volumes for each cluster per group). For the between-group analysis, no significant clusters were observed such that non-ε4 > ε4.