正常老年人数字记忆功能的磁共振成像

摘要

目的 探讨正常健康老年人数字工作记忆的脑加工神经机制.方法 实验采用事件相关设计,利用功能磁共振技术(fMRI)对15例正常老年人进行数字工作记忆的数据采集,数据采用AFNI 软件进行数据分析和脑功能区活动图像,分析编码期、保持期、提取期的脑激活情况.结果 进行数字记忆工作任务时,15例正常老年人平均反应时为(1 102.4±99.3)ms,正确率为(95.2±2.5)%.数字工作记忆的编码期激活双侧中央前回、双侧梭状回、双侧枕下回、双侧小脑;保持期脑激活位于左侧中央前回、中央后回、岛叶、额下回及额中回、双侧壳核、双侧梭状回及右额下回也有少量激活;提取期脑激活位于双侧壳核、双侧丘脑、双侧岛叶、双侧顶下小叶、左侧额下回、左侧中央后回、左侧颞中回、左侧颞下回、双侧小脑.结论 左侧额叶在正常老年人脑数字工作记忆中起重要作用,其他脑区也共同参与完成数字工作记忆的信息处理过程.%Objective To explore the activated brain regions of digital working memory in healthy old people using functional magnetic resonance imaging (fMRI).Methods fMRI was acquired in 15 healthy old subjects when they received digital working memory experiment with event-related design.AFNI was used to process data and localize functional areas of brain.Results The reaction time and correct ratio of the healthy older volunteers were ( 1 102.4 ± 99.3 ) ms and (95.2 ± 2.5 )％, respectively.Bilateral precentral gyrus, fusiform gyms, inferior occipital gyrus, cerebellum were activated during encode phase of the digital working memory task.Left precentral gyrus,postcentral gyms, insula lobe, inferior and middle frontal gyrus, bilateral fusiform gyrus, putamen and right inferior frontal gyrus were activated during maintain phase.Bilateral putamen, thalamus, insula lobe, parietal lobule, left inferior frontal gyrus, postcentral gyrus, right superior and inferior temporal gyrus and bilateral cerebellum were activated during retrieve phase.Conclusions Left frontal lobe plays an important role in manipulating the information of the digital working memory.Left temporal lobe, parietal lobe and some other brain regions are also indispensable in the process.