年轻人与老年人简单乘法运算之功能磁共振成像研究

目的应用fMRI技术探讨中国青年和老年人群在简单运算任务下脑激活模式及其与行为学之间的关系。方法分别对青年组(19例)和老年组(20例)健康志愿者进行对照任务和简单运算任务下的fMRI检查。结果两组受试者受教育程度(P=0.125)、智力水平(P=0.921),以及完成对照任务(P=0.142)和简单乘法运算任务(P=0.880)之正确率差异无统计学意义,但老年组受试者完成对照任务(P=0.000)和简单乘法运算任务(P=0.005)反应时间明显延长。青年组受试者在任务刺激下可激活右侧缘上回并向顶内沟和颞中上回后部延伸,中央前回和运动前区、前额叶,左侧缘上回并向颞上回后部和角回延伸,顶内沟区域、颞中下回,内侧后扣带回、楔前叶、辅助运动区、海马沟、海马旁回及前额叶内侧;老年组受试者则分别激活右侧缘上回和顶下区域并向颞中上回后部延伸,中央前回和运动前区、前额叶,左侧缘上回和角回并向顶下延伸,中央前回和运动前区、岛叶及前额叶,内侧后扣带回和中央旁小叶、前扣带回及前额叶内侧;两组受试者共激活脑区包括顶下区域、楔前叶、中央前后回和额顶叶网络,以及颞叶、海马旁回、钩回、屏状核和后扣带回等皮质下结构。结论数学事实提取相关网络的主要成分受年龄影响较小,老年人群的任务激活脑区主要向任务相关顶区集中。

An fMRI investigation on simple multiplication in younger and older adults

Objective To investigate the cortical activation patterns and their correlation with behavioristics during simple multiplication in Chinese younger and older adults. Methods Functional magnetic resonance imaging （fMRI） was performed as healthy younger and older participants resolving arithmetic and control problems. Results Totally 39 right-handed healthy adults were recruited in this study, including 19 （11 females, 8 males） younger and 20 （12 females, 8 males） older subjects. Age （P = 0.000） was significantly different between 2 groups, and no significant difference was observed in years of education （P = 0.125） and IQ scores （P = 0.921）. The accuracy for simple multiplication （P = 0.880） and control task （P = 0.142） were not significantly different between 2 groups, however differences were observed in reaction time for experimental （P = 0.005） and control （P = 0.000） tasks. In younger group, activation in right hemisphere included inferior parietal lobule with an extending to the intraparietal sulcus and superior/ middle temporal gyrus, precentral gyrus, premotor cortex and prefrontal cortex. Activation of supramarginal gyrus, angular gyrus, temporal lobe was found in the left. And activation in medial cingulate gyrus, precuneus, parahippocampal gyrus, uncus, and supplementary motor area （SMA） was also observed. In older group, supramarginal gyrus, inferior parietal lobule, precentral gyrus, premotor cortex and prefrontal cortex were activated in the right hemisphere. Left angular gyrus, supramarginal gyrus, precentral gyrus,premotor cortex, insula and prefrontal cortex were also activated, as well as cingulate gyrus, paracentral lobule and prefrontal cortex in the medial part. The conjunction analysis of the fMRI data revealed in a distributed network consisting of inferior parietal area, precuneus, precentral/postcentral gyrus and prefrontal lobe, as well as some subcortical areas. Conclusions The major components of the network subserving simple multiplication ar