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

额顶网络在一般的数字认知和具体的空间-数字联系中起着至关重要的作用。经颅直流电刺激(TDC)对不同皮质区域的数字处理的调制为了解它们共享的和不同的神经认知因果网络提供了洞察力。以前的刺激研究显然是针对左侧前额叶皮质(PFC)的阴极TDC来调节空间-数字联系，但区域特异性尚不清楚。本项目系统地分离不同电极配置的影响，并改变目标和返回电极的位置，以获得区域特异性。WP1将考察在大小比较任务中涉及数字大小(距离效应)和空间-数字加工(SNARC效应)的不同网络站点的因果贡献，并将这些影响与反应抑制功能(控制任务)进行比较。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相互作用的即时生理效应以及空间-数字关联。血流动力学测量有望显示额叶-顶叶数值处理网络导致的额叶后顶叶皮质对前额叶tDCs的跨皮质反应。结果证实了人类数字大小加工和空间-数字联系的神经元实现，以及tdcs效应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.