中国科学院心理研究所机构知识库

目的:探索脑功能老化异质性的相关机制。方法:10例成功老龄(SA)、10例常态老龄(UA)和9例轻度认知功能损害(MCI)患者进行词汇流畅性作业(VFT)的fMRI检查,比较脑激活表现。结果:SA与UA均明显激活顶叶、额叶、扣带前回及枕叶,MCI除右侧额叶外激活普遍低下; SA激活强度大于UA,但差异无统计学意义,二者激活强度均高于MCI,差异有统计学意义(P<0.01)。SA左前额叶(尤其左侧前额叶背外侧皮质)激活显著,UA与MCI激活相对减弱,差异有统计学意义(P=0.01)。SA脑激活呈一致优势侧偏(偏侧化指数LIs=0.46),UA和MCI脑激活总体无偏侧性(LIs分别为-0.12和-0.06); (4)SA与UA均有显著枕叶激活,MCI激活不明显。结论:脑老化过程中存在着异质性,涉及了复杂的脑功能机制; 左侧前额叶背外侧皮质激活程度和偏侧化指数可作为衡量脑功能老化水平的参考指标。

Objective：To explore the heterogeneity of aging brain. Methods：Blood oxygenation level dependent functionalmagnetic resonance imaging was performed on 10 subjects meeting the standards of successful aging (SA) , 9 subjects meeting the standards of usual aging (UA) , and 9 subjects meeting the criteria of mild cognitive impairment (MCI) , all age, and sex-matched, under stimulation of verbal fluent test (VFT). The activation level of different regions of interest (ROI) , laterality index, and the activation level of occipital lobe were analyzed. Results：The achievement in VFT of the SA group was greater than that of the UA group, and much greater than that of the MCI group with significant differences between any 2 groups (all P <0.05) except in the task of“names of vegetables”. The activation volume of the SA group was greater than that of the UA group, and much greater than that of the MCI group. The main activated regions of the SA and UA groups included left precuneus, anterior cingulated gyrus, middle frontal gyrus, superior frontal gyrus and inferior parietal lobule, and bilateral occip ital lobes. The main activated regions of the MCI group included the bilateral p refrontal lobe. The intensity of activation was not significantly different between the SA and UA group s, however, was significantly different between the SA and MCI group s and between the UA andMCI groups. The laterality index (LI) was 0. 46 in the SA group, significantly higher than those of the UA group (-0.12) and MCI group (-0.06) (both P<0. 01) , however, without a significant difference between the UA group and MCI group. The activation of left prefrontal lobe in the SA group wasmore obvious than that in the UA group, and much more obvious than that in the MCI group with a significant difference between the UA and MCI groups as well ( all P < 0. 01). The activation volume of the left dorsal lateral prefrontal cortex (DLPFC) in the SA group was 787 voxels, significantly greater than that in the UA group (292 voxels) and MCI group (0 voxel) (all P<0.01). Conclusion：Heterogeneity exists in the course of aging, associated with comp licated brain mechanism. The activation level ofDLPFC and LI may be used as sensitive indexes in evaluation of the brain function of the elderly.