There is growing evidence for a positive correlation between measures of muscular strength and cognitive abilities. However, the neurophysiological correlates of this relationship are not well understood so far. The aim of this study was to investigate cortical hemodynamics [i.e., changes in concentrations of oxygenated (oxyHb) and deoxygenated hemoglobin (deoxyHb)] as a possible link between measures of muscular strength and cognitive performance. In a cohort of younger adults (n = 39, 18–30 years), we assessed (i) handgrip strength by a handhold dynamometer, (ii) short-term working memory performance by using error rates and reaction times in the Sternberg task, and (iii) cortical hemodynamics of the prefrontal cortex (PFC) via functional near-infrared spectroscopy (fNIRS). We observed low to moderate negative correlations (rp = ~ − 0.38 to − 0.51; p < 0.05) between reaction time and levels of oxyHb in specific parts of the PFC. Furthermore, we noticed low to moderate positive correlations (rp = ~ 0.34 to 0.45; p < 0.05) between reaction times and levels of deoxyHb in distinct parts of the PFC. Additionally, higher levels of oxyHb (rp (35) = 0.401; p = 0.014) and lower levels of deoxyHb (rp (34) = − 0.338; p = 0.043) in specific parts of the PFC were linked to higher percentage of correct answers. We also found low to moderate correlations (p < 0.05) between measures of handgrip strength and levels of oxyHb (rp = ~ 0.35; p < 0.05) and levels of deoxyHb (rp = ~ − 0.25 to − 0.49; p < 0.05) in specific parts of the PFC. However, there was neither a correlation between cognitive performance and handgrip strength nor did cortical hemodynamics in the PFC mediate the relationship between handgrip strength and cognitive performance (p > 0.05). The present study provides evidence for a positive neurobehavioral relationship between cortical hemodynamics and cognitive performance. Our findings further imply that in younger adults higher levels of handgrip strength positively influence cortical hemodynamics although the latter did not necessarily culminate in better cognitive performance. Future research should examine whether the present findings can be generalized to other cohorts (e.g., older adults).

中文翻译：

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皮质血流动力学作为握力和认知表现的函数：针对年轻人的横断面 fNIRS 研究

越来越多的证据表明肌肉力量测量与认知能力之间存在正相关关系。然而，迄今为止，这种关系的神经生理学相关性尚不清楚。本研究的目的是调查皮质血流动力学（即氧合血红蛋白 (oxyHb) 和脱氧血红蛋白 (deoxyHb) 浓度的变化）作为肌肉力量测量和认知表现之间可能的联系。在一组年轻人（n = 39、18-30 岁）中，我们评估了（i）通过手持测力计的握力，（ii）通过使用 Sternberg 任务中的错误率和反应时间来评估短期工作记忆表现， (iii) 通过功能性近红外光谱 (fNIRS) 测量前额皮质 (PFC) 的皮质血流动力学。我们观察到反应时间与 PFC 特定部分的 oxyHb 水平之间存在低至中度负相关性（rp = ~ − 0.38 至 − 0.51；p < 0.05）。此外，我们注意到 PFC 不同部分的反应时间和脱氧血红蛋白水平之间存在低至中度正相关性（rp = ~ 0.34 至 0.45；p < 0.05）。此外，PFC 特定部位较高的 oxyHb 水平 (rp (35) = 0.401；p = 0.014) 和较低的 deoxyHb 水平 (rp (34) = − 0.338；p = 0.043) 与较高的正确答案百分比相关。我们还发现握力测量值与氧血红蛋白水平 (rp = ~ 0.35; p < 0.05) 和脱氧血红蛋白水平 (rp = ~ − 0.25 至 − 0.49; p < 0.05) 之间存在低至中度相关性 (p < 0.05)。 PFC 的特定部分。然而，认知表现和握力之间既不存在相关性，前额皮层的皮质血流动力学也不介导握力和认知表现之间的关系（p > 0.05）。本研究为皮质血流动力学与认知表现之间的积极神经行为关系提供了证据。我们的研究结果进一步表明，在年轻人中，较高水平的握力会对皮质血流动力学产生积极影响，尽管后者不一定会带来更好的认知表现。未来的研究应该检验目前的研究结果是否可以推广到其他人群（例如老年人）。