Weigl Michael, Mecklinger Axel, Rosburg Timm
Department of Psychology, Experimental Neuropsychology Unit, Saarland University, 66041 Saarbrücken, Germany.
Department of Psychology, Experimental Neuropsychology Unit, Saarland University, 66041 Saarbrücken, Germany.
Clin Neurophysiol. 2016 May;127(5):2263-72. doi: 10.1016/j.clinph.2016.01.024. Epub 2016 Feb 11.
To investigate the contribution of the left dorsolateral prefrontal cortex (DLPFC) to attentive and pre-attentive stimulus discrimination via transcranial direct current stimulation (tDCS).
Novelty- and target-P3 as indexes of attentive stimulus discrimination and the mismatch negativities (MMNs) for duration, intensity, and frequency deviants as indexes of pre-attentive stimulus discrimination were recorded before and after delivering anodal and cathodal tDCS to the left DLPFC.
MMN amplitudes for all kinds of deviants decreased from pre- to post-tDCS measurement. For duration and intensity deviants, this pre-post reduction was stronger after anodal tDCS, as compared to the decrease after sham stimulation. No such modulation was found for the MMN to frequency deviants. Neither the novelty-P3 nor the target-P3 was modulated by tDCS.
The selective MMN decrease after anodal (excitatory) stimulation of the left DLPFC suggests that this region either inhibits the processing of specific auditory changes or modulates the habituation of the MMN to certain kinds of deviances.
Our finding that left frontal anodal tDCS reduces the MMN to duration and intensity deviants further highlights the contribution of frontal brain regions to MMN generation and extends previous reports of reduced MMNs to frequency deviants after right frontal anodal tDCS.
通过经颅直流电刺激（tDCS）研究左侧背外侧前额叶皮质（DLPFC）对注意力集中和注意力前刺激辨别能力的贡献。
在对左侧DLPFC进行阳极和阴极tDCS之前和之后，记录作为注意力集中刺激辨别指标的新奇性P3和目标P3，以及作为注意力前刺激辨别指标的持续时间、强度和频率偏差的失匹配负波（MMN）。
从tDCS测量前到测量后，所有类型偏差的MMN波幅均降低。对于持续时间和强度偏差，与假刺激后的降低相比，阳极tDCS后这种前后降低更为明显。对于频率偏差的MMN未发现这种调制。tDCS对新奇性P3和目标P3均无调制作用。
左侧DLPFC阳极（兴奋性）刺激后MMN选择性降低表明，该区域要么抑制特定听觉变化的处理，要么调节MMN对某些类型偏差的习惯化。
我们的发现，即左侧额叶阳极tDCS降低了对持续时间和强度偏差的MMN，进一步突出了额叶脑区对MMN产生的贡献，并扩展了先前关于右侧额叶阳极tDCS后对频率偏差的MMN降低的报道。
