θ节律串刺激对视觉空间注意的行为学及事件相关电位研究

A research on the behavior and event- related potential of visual spatial attention by continuous theta burst stimulation

目的:研究持续性θ节律串刺激(c TBS)对视觉空间注意障碍的作用机制。方法:将30例正常受试者随机分为实验组(刺激组)和对照组(假刺激组),两组经过TBS刺激后进行事件相关电位(ERP)实验,实验范式为"提示—靶",包括范围提示和汉字提示,范围提示为"大"圈和"小"圈,汉字提示为"大"字和"小"字。TBS刺激参数频率为30Hz,刺激强度为刺激器输出的50%,刺激部位为受试者右侧大脑的顶叶后部(P4),刺激脉冲801串,刺激间隔100ms。结果:实验组和对照组在汉字提示和范围提示时,反应时表现出提示等级效应(P<0.05)。实验组与对照组比较,在汉字提示下P1、P2波幅明显低于对照组(P<0.05),在范围提示下PO4部位的P1、N1、N2波幅明显低于对照组(P<0.05)。实验组汉字提示与范围提示比较,范围提示时P1、P2、N2波幅更大(P<0.05);对照组汉字提示与范围提示比较,范围提示时P1、N1、P2波幅更大(P<0.05)。结论:对右侧顶后叶皮质(PPC)进行抑制性c TBS刺激,能够影响大脑皮质神经元兴奋性活动,尤其会影响对左侧靶目标的识别及加工。

Objective： To investigate the mechanism of continuous theta burst stimulation（cTBS） on visual spatial attention disorder.Method： Thirty normal subjects were randomly divided into experimental group（c TBS, n=15） and control group（sham c TBS, n=15）. Event-related potentials（ERP） was used and the test paradigm was＂cue-target＂including the range cue and the character cue. The range cue included big circle and small circle and the character cue included big character and small character. The frequency of TBS was 30 Hz and the intensity was50% of output of the stimulator. The stimulation site was over the right posterior parietal cortex（PPC）（P4）.The stimulation provide 801 pulses strings and the stimulus interval was 100 ms.Result： For range cue and character cue, there were obvious range cue level effects in both two groups（P〈0.05）. Compared with the control group, P1 and P2 amplitudes were significantly lower in experimental groupfor the character cue and P1, N1 and N2 amplitudes at PO4 position were significantly lower in experimental group for the range cue（P〈0.05）. In experimental group, P1, P2 and N2 amplitude were higher for the range cue（P〈0.05）. In control group, P1, N1 and P2 amplitude, were higher for the range cue（P〈0.05）.Conclusion： Cortical neuronal excitability could be inhibited with c TBS stimulation over the right PPC, that could influence target recognition and processing especially on the left side.