大学生数字长时记忆的脑功能磁共振定位研究

目的 通过功能磁共振成像(fMRI)技术检测健康人脑数字长时记忆认知功能的脑区.方法 22名右利手健康志愿者进行一项数字长时记忆任务时行fMRI扫描.实验采用组块设计并选用统计参数图(SPM99)软件行数据分析和脑功能区定位,记录各激活脑区的像素值并计算偏侧化指数LI值.结果 采用单样本t检验,阈值设为P＜0.0001时,主要激活的脑区为左额中回(激活强度T值=9.68)和右侧小脑(激活强度T值=9.85),皮质下的丘脑(激活强度T值=6.72)和尾状核(激活强度T值=6.58)也被激活.激活脑区像素值的LI值为0.51.结论 数字长时记忆认知过程是由大脑、小脑及皮质下结构共同协作完成的,且存在左半球优势现象.

Neural representations of long-term digital memory: an fMRI study

Objective To investigate the neural representations of long-term digital memory in human brain by functional magnetic resonance imaging (fMRI) technique. Methods 22 right-handed normal volunteers were recruited to participate in a test of long-term digital memory while the fMRI data were recorded. Control tasks were performed for the block-design. SPM 99 was used to analyze the data and to obtain the activated brain regions.Numbers of activated voxels were used to calculate lateralization index (LI). Results When the threshold was set as P＜0. 0001 ,using a one-sample t -test,the middle gyrus of the left frontal lobe(t=9.68) and the right cerebellum ( t = 9.85 ) were activated remarkably during the memory task. The subcortical structures including the thalamus (t=6.72) and the caudate (t=6.58) were also obviously activated during the memory task. LI of the numbers of activated voxels was 0.51. Conclusions The subcortical structures and the cerebellum as well as the cerebral cortex are collaborative to contribute to long-term digital memory function in human brain. The results also reveal that the functional areas of long-term digital memory in human brain are localized with the functional lateralization in the left hemisphere.