Movement to Health M2H, Montpellier-1 University, EuroMov, 700 Avenue du Pic Saint Loup, 34090 Montpellier, France.
Neurosci Res. 2013 Jul;76(3):156-62. doi: 10.1016/j.neures.2013.04.006. Epub 2013 May 9.
Functional near-infrared spectroscopy (fNIRS) is suitable for investigating cerebral oxygenation changes during motor and/or mental tasks. In the present study, we investigated how an additional mental load during a motor task at two submaximal loadings affects the fNIRS-measured brain activation over the right prefrontal cortex (PFC). Fifteen healthy males performed isometric grasping contractions at 15% and 30% of the maximal voluntary contraction (MVC) with or without an additional mental (i.e., arithmetic) task. Mental performance, force variability, fNIRS and subjective perception responses were measured in each condition. The performance of the mental task decreased significantly while the force variability increased significantly at 30% MVC as compared to 15% MVC, suggesting that performance of dual-task required more attentional resources. PFC activity increased significantly as the effort increased from 15% to 30% MVC (p<.001). Although a larger change in the deoxyhemoglobin was observed in dual-task conditions (p=.051), PFC activity did not change significantly as compared to the motor tasks alone. In summary, participants were unable to invest more attention and effort in performing the more difficult levels in order to maintain adequate mental performance.
功能近红外光谱（fNIRS）适合研究运动和/或心理任务期间大脑氧合变化。在本研究中，我们研究了在两种次最大负荷下进行运动任务时额外的心理负荷如何影响右前额叶皮层（PFC）的 fNIRS 测量脑激活。15 名健康男性以最大自主收缩（MVC）的 15%和 30%进行等长抓握收缩，同时或不进行额外的心理（即算术）任务。在每种情况下都测量了心理任务的表现、力变异性、fNIRS 和主观感知反应。与 15% MVC 相比，30% MVC 时心理任务的表现明显下降，力变异性明显增加，这表明双任务的表现需要更多的注意力资源。当努力从 15%增加到 30% MVC 时，PFC 活动显著增加（p<.001）。尽管在双重任务条件下观察到脱氧血红蛋白的变化更大（p=.051），但与单独进行运动任务相比，PFC 活动没有显著变化。总之，参与者无法投入更多的注意力和努力来完成更困难的水平，以维持足够的心理表现。
