Fig. 4

Possible brain mechanisms underlying the development and reversion of mild cognitive impairment. For the development of mild cognitive impairment, the disappearance of atrophy synchronism between the hippocampal region and the frontal and lateral temporal lobes played a key role, while the reversion of mild cognitive impairment was mainly due to accelerated atrophy in the hippocampus. Abbreviations: DMN, default mode network; FPN, frontoparietal network; Hipp, hippocampal; sNC, stable normal cognition; pNC, progressive normal cognition; non-rMCI, non-reversed mild cognitive impairment; rMCI, reversed mild cognitive impairment