人脑注意网络神经基础的功能MRI研究

目的采用事件相关功能MRI(event-related functional MRI，ER-fMRI)方法确认前后注意网络的神经基础以及两者的相互关系。方法对8例右利手的健康志愿者进行了视觉定向中返回抑制效应与Stroop色词干扰任务相结合的实验测试，同时采用Siemens Sonata 1．5T成像系统，采集其脑部的fMRI数据，通过功能神经成像分析(analysis of functional neuroimage，AFNI)软件进行统计分析得到脑功能活动的图像。结果8例受试者中6例的资料符合研究条件而被采用。(1)标识前注意网络(AAN)的Stroop色词任务和标识后注意网络(PAN)的返回抑制(IOR)任务的相关脑组织激活区与有关实验结果类似；(2)提示位置相关脑组织激活区见于左侧顶下小叶(BA40)、MT／V5区、右侧背外侧前额叶(BA9)和左侧前扣带回(ACC)；非提示位置相关脑组织激活区见于右侧顶上小叶(BA7)和双侧MT／V5区。结论AAN对PAN起调节作用，同时PAN也影响AAN作用的充分发挥，AAN和PAN是相互联系、相互作用的2个注意子网络；ER-fMRI是合理修正原有的关于认知活动模型和理论的一种有效手段。

Functional MRI studies of the neural mechanisms of human brain attentional networks

Objective To identify the neural mechanisms of the anterior attention network (AAN) and posterior attention network (PAN), investigate the possible interaction between them with event-related functional MRI(ER-fMRI). Methods Eight right-handed healthy volunteers participated in the experiment designed with inhibition of return in visual orienting and Stroop color-word interference effect. The fMRI data were collected on Siemens 1.5 T Sonata MRI systems and analyzed by AFNI to generate the activation map. Results The data sets from 6 of 8 subjects were used in the study.The functional localizations of the Stroop and IOR, which manifest the function of the AAN and PAN respectively, were consistent with previous imaging researches. On cued locations, left inferior parietal lobule(IPL), area MT/V5, right dorsolateral prefrontal cortex (DLPFC) and left anterior cingulated cortex (ACC) were significantly activated. On uncued locations, right superior parietal lobule(SPL)and bilateral area MT/V5 were significantly activated. Conclusion The AAN exerts control over the PAN, while its function can be in turn modulated by the PAN. There are interaction between the AAN and PAN. In addition, it is also proved that ER-fMRI is a feasible method to revise preexisting cognitive model and theory.