青老年组不同难度下心算活动的脑功能磁共振成像研究  

The Neural Correlates of Mental Calculation: An fMRI Study on the Effects of Aging and Task Difficulty

作　　者：刘昌[1] 翁旭初[2] 李恩中[3] 李德明[4] 马林[5] 

机构地区：[1]南京师范大学认知科学实验室,南京210097 [2]中国科学院心理研究所脑高级功能实验室,北京100101 [3]中国科学院心理研究所心理健康重点实验室,北京100101 [4]首钢总医院磁共振室,北京100041 [5]中国人民解放军总医院放射室,北京100041

出　　处：《心理科学》2005年第4期845-848,共4页Journal of Psychological Science

基　　金：全国优秀博士学位论文作者专项资金(200006);国家自然科学基金(30128005;30070265)资助项目

摘　　要：应用功能磁共振成像技术研究不同心算难度下脑区的活动以及年龄的影响。14名志愿者(20～29岁青年和60～69岁老年被试各7名)参加了该实验。实验任务为2个难度水平的连续减法心算,分别为1000-3和1000-17。结果表明:(1)心算加工激活了额叶和顶叶的许多脑区;(2)大脑左半球是心算加工的优势半球,但随着心算难度加大,大脑一侧化程度下降,而年老加剧了这一趋势;(3)青年组进行简单心算(1000-3)时,额中回未见明显激活,而老年组进行简单心算时,该脑区被明显激活。总体上,额叶和顶叶在心算活动中起着重要作用,而任务难度和年龄对心算加工时脑活动的影响以额中回区最为明显。Functional magnetic resonance imaging （fMRI） was used to investigate the effects of aging and task difficulty on brain activation engaged in mental calculation. Seven young and seven old volunteers performed two tasks during MRI scanning. In one task, the subjects were instructed to continually subtract three from 1000, and in the more difficult task, to continually subtract 17 from 1000. A large set of regions in the frontal and parietal cortices was activated during mental calculation. Although there was greater activation in the left hemisphere than in the right hemisphere, there was more involvement of the right hemisphere with increased arithmetic difficulty and age. In the 1000-3 task, activation in the medial prefrontal gyrus （MPFG） was observed only in the old group. These results suggest that both frontal and parietal lobes play important roles in mental calculation, and the involvement of these regions, particularly MPFG, is influenced by arithmetic difficulty and aging.

关 键 词：心算活动 脑功能磁共振成像 青老年组 生理心理学 信息加工模式 

分 类 号：B844.3[哲学宗教—发展与教育心理学]