持续短阵快速脉冲刺激前额叶皮质对视空间注意功能的调控机制

关键词：视空间注意  前额叶  短阵快速脉冲刺激  经颅磁刺激

Keywords:visuospatial attention  prefrontal cortex  theta burst stimulation  tramscranial magnetic stimulation

摘要：

      摘要 目的：探讨持续短阵快速脉冲刺激背外侧前额叶皮质对视空间注意功能的调控机制。 方法：选取志愿受试者40人参加本实验，男女各半，全部为右利手。采用持续短阵快速脉冲经颅磁刺激（cTBS,TMS）背外侧前额叶皮质（DLPFC）后进行注意网络测试（ANT），所有受试者均按照随机顺序进行真/假刺激左/右侧背外侧前额叶脑区。 结果：持续短阵快速脉冲经颅磁刺激施加于前额叶时，不同提示和刺激类型的平均反应时均无明显改变。右侧额叶抑制，警觉和执行功能受损（P＜0.05）；左侧额叶抑制，反而出现警觉和执行功能增强（P＜0.05）。 结论：背外侧前额叶皮质主要与警觉和执行功能有关，具有明显的右侧半球优势。在双侧大脑半球同源脑区间，视空间注意认知过程存在竞争性抑制。

Abstract:

      Abstract Objective: To probe the modulatory effects of continuous theta burst stimulation（cTBS） over the dorsolateral prefrontal cortex（DEPFC） on visuospatial attention using attention network test (ANT) paradigm in healthy human subjects. Method: ANT was used to test forty healthy subjects after cTBS on the left or right DLPFC. The ANT provided measures for three different components of visual attention: alerting, orienting and executive control. Result: During this task, subjects with real left-DLPFC cTBS showed significant improvement in network effect indices compared with the shams on alerting and conflict, and significant deficit on orienting（P<0.05）. Moreover, compared with the sham cTBS condition, the real right-DLPFC cTBS resulted in significant decreases in efficiency of alerting and conflict,and significant increase in orienting index（P<0.05）.Furthermore, there were significant differences in alerting,orienting and conflict effect indices between in the real left-DLPFC and in the right-DLPFC. Conclusion: These results suggest that right DLPFC plays a pivotal role in alerting and executive control process. In addition, the present study supports the model of inter-hemispheric rivalry for visuospatial attention.