Fig. 3.

Brain activities in all contrasts. a The motor imagery (MI) task evoked activation in the bilateral middle occipital gyrus (BA 37, 18), the bilateral premotor cortex (BA 6), the right inferior parietal lobules (BA 40), and the left superior and inferior parietal lobules (BA7, 40). b The mental rotation of a hand (H-MRot) task evoked activation in the bilateral middle occipital gyrus (BA 18), the bilateral premotor cortex and supplementary motor area (BA 6), the right inferior parietal lobules (BA 40), and the left superior and inferior parietal lobules (BA7, 40). c The mental rotation of an object (O-MRot) task evoked activation in the bilateral middle occipital gyrus (BA 18) and the right premotor cortex (BA 6). d-e Contrasts were defined as follows: H-MRot minus MI tasks and MI minus H-MRot tasks. The premotor area, the supplementary motor area (BA 6), and the inferior parietal lobe (BA 40) were dominant in the MI task. Blue circles indicate activated premotor areas. Green circles indicate activated supplementary motor areas. Yellow circles indicate activated parietal association areas. f-g Contrasts were defined as follows: O-MRot minus H-MRot tasks and H-MRot minus O-MRot tasks. Premotor areas were dominant in H-MRot tasks. a-c: group analysis, n = 26, P < 0.05, FWE. d-g: group analysis, n = 26, P < 0.001, uncorrected