Cross-cortical implementation of spatial-numerical associations revealed by transcranial direct current stimulation and near-infrared-spectroscopy

额顶叶网络在一般的数字认知和特定的空间-数字关联中起关键作用。经颅直流电刺激（tDCS）对不同皮层区域的数值处理的调节提供了对其共享和独特的神经认知因果网络的见解。以往的刺激研究明显是针对左前额叶皮层（PFC）的阴极tDCS调节空间-数值关联，但区域特异性不明确。本项目系统地解开了不同电极配置的影响，并改变了目标和返回电极的位置，以获得区域特异性。WP1将研究大小比较任务中涉及数值大小（距离效应）和空间-数值处理（SNARC效应）的不同网络位点的因果关系，并将这些效应与反应抑制功能（控制任务）进行对比。在WP2中，与tDCS同时进行的近红外光谱（NIRS）皮质血流动力学活动成像可以揭示tDCS相互作用与空间-数值关联的直接生理效应。血流动力学测量预计将证明由于额-顶叶数值处理网络，后顶叶皮层对前额叶tDCS的跨皮质反应。结果证实了人类数字量级处理和空间-数字关联的神经元执行，以及tDCS在数字认知中的基本原理。

Fronto-parietal networks are critically involved in numerical cognition in general and spatial-numerical associations in specific. The modulation of numerical processing by transcranial direct current stimulation (tDCS) over different cortical regions provides insights into their shared and distinct neurocognitive causal networks. Previous stimulation studies were apparently specific to cathodal tDCS of the left prefrontal cortex (PFC) for modulation spatial-numerical associations, but regional specificity was not clear. The present project systematically disentangles effects of different electrode configurations and varies both target and return electrode positions to obtain regional specificity. WP1 will investigate the causal contributions of different network sites involved in numerical magnitude (distance effect) and spatial-numerical processing (SNARC effect) in magnitude comparison tasks, and contrast these effects to response inhibition functions (control task). In WP2, imaging of cortical hemodynamic activity with near-infrared spectroscopy (NIRS) concurrent to tDCS can enlighten the immediate physiological effects of tDCS interactions with spatial-numerical associations. The hemodynamic measurements are anticipated to demonstrate cross-cortical responses to prefrontal tDCS in posterior parietal cortex due to the fronto-parietal numerical processing network. Results corroborate the neuronal implementation of numerical magnitude processing and spatial-numerical associations in humans, and basic principles of tDCS effects in numerical cognition.