Abstract：
Phasic cardiac vagal activity (CVA), reflecting ongoing, moment-to-moment psychophysiological adaptations to environmental changes, can serve as a predictor of individual difference in executive function, particularly executive performance. However, the relationship between phasic CVA and executive function demands requires further validation because of previous inconsistent findings. Moreover, it remains unclear what types of phasic changes of CVA may be adaptive in response to heightened executive demands. This study used the standard N-back task to induce different levels of working memory (WM) load and combined functional Near-Infrared Spectroscopy (fNIRS) with a multipurpose polygraph to investigate the variations of CVA and its interactions with cognitive and prefrontal responses as executive demands increased in fifty-two healthy young subjects. Our results showed phasic decreases in CVA as WM load increased (t (51) = -3.758, p < 0.001, Cohen\'s d = 0.526). Furthermore, phasic changes of CVA elicited by increased executive demands moderated the association of cognitive and cerebral hemodynamic variations in the prefrontal cortex (B = 0.038, SE = 0.014, p < 0.05). Specifically, as executive demands increased, individuals with larger phasic CVA withdrawal showed a positive relationship between cognitive and hemodynamic variations in the prefrontal cortex (β = 0.281, p = 0.031). No such significant relationship was observed in individuals with smaller phasic CVA withdrawal. The current findings demonstrate a decrease in CVA with increasing executive demands and provide empirical support for the notion that a larger phasic CVA withdrawal can be considered adaptive in situations requiring high executive function demands.
摘要：
相位性心脏迷走神经活动(CVA),反映正在进行的，对环境变化的即时心理生理适应，可以预测执行功能的个体差异，尤其是执行绩效。然而,由于之前的发现不一致,阶段性CVA与执行功能需求之间的关系需要进一步验证.此外，目前尚不清楚哪些类型的CVA阶段性变化可能是适应执行要求提高的适应性变化.这项研究使用标准的N-back任务来诱导不同水平的工作记忆（WM）负荷，并将功能近红外光谱（fNIRS）与多功能测谎仪相结合，以研究CVA的变化及其与认知和前额叶反应的相互作用作为52名健康年轻受试者的执行需求增加。我们的结果表明，随着WM负荷的增加，CVA呈阶段性下降（t（51）=-3.758，p<0.001，Cohen\sd=0.526）。此外，执行需求增加引起的CVA的阶段性变化减轻了前额叶皮层的认知和脑血流动力学变化的关联（B=0.038，SE=0.014，p<0.05）。具体来说,随着高管要求的增加，具有较大阶段性CVA戒断的个体显示前额叶皮层的认知和血流动力学变化之间存在正相关关系(β=0.281,p=0.031).在具有较小的阶段性CVA戒断的个体中未观察到这种显着的关系。当前的发现表明，随着执行需求的增加，CVA的降低，并为以下观点提供了经验支持：在需要高执行功能需求的情况下，可以认为更大的阶段性CVA退出是适应性的。
