正常人参数性数字n-back工作记忆任务的去激活网络:fMRI研究

目的:探讨工作记忆任务诱发去激活(Task induced deactivation,TID)脑区及其意义。方法:正常受试者35名,采用参数性数字n-back任务(n为1、2、3)行fMRI,0back作为对照任务。根据受试者在实验过程中3back任务的行为学表现,将准确率为≥85%的受试者纳入高执行表现正常受试者(High performing normal subjects,HPNS)组。采用SPM2软件进行功能数据预处理、统计分析和结果显示。结果:HPNS中TID脑区包括:前额叶皮层内侧部(medialprefrontal cortex,MPFC);扣带;右侧额下回(BA47);双侧颞叶多个脑区。在2back负载水平之内,随着负载增加,TID脑区去激活程度增加,但在2back负载之后,大多TID脑区的去激活呈平台期表现。结论:TID网络的存在对WM任务的正确执行是必须的。

Deactivation Network of Parametric Digit n-back Working Memory Task in Normal Subjects: An fMRI Study

Objective: To explore task induced deactivation(TID) brain regions in WM task and its significance.Methods: 35 normal subjects receiving fMRI with a parametric digit n-back task(n=1,n=2,n=3 task) were employed,with an 0-back control condition.On the basis of behavioral performance of 3 back task in experiment,normal subjects whose accuracy exceeding or equal to 85% were included in high performing normal subjects(HPNS) group.Preprocessing,statistical analysis and result display of functional data were performed by SPM2.Results: For HPNS,task induced deactivation brain regions included: medial prefrontal cortex(MPFC),cingulate,right inferior frontal gyrus(BA47),multiple regions in bilateral temporal lobe.Within the scope of 2back load level,deactivation of TID brain regions increased with increasing load,and most TID regions showed platform manifestation once the 2back level was exceeded.Conclusion: TID network is essential for accurate performance of WM.