Yuan Peng, Koppelmans Vincent, Reuter-Lorenz Patricia A, De Dios Yiri E, Gadd Nichole E, Wood Scott J, Riascos Roy, Kofman Igor S, Bloomberg Jacob J, Mulavara Ajitkumar P, Seidler Rachael D
School of Kinesiology, University of Michigan Ann Arbor, MI, USA.
Department of Psychology, University of Michigan Ann Arbor, MI, USA.
Front Syst Neurosci. 2016 Aug 23;10:71. doi: 10.3389/fnsys.2016.00071. eCollection 2016.
Head-down tilt bed rest (HDBR) has been used as a spaceflight analog to simulate the effects of microgravity exposure on human physiology, sensorimotor function, and cognition on Earth. Previous studies have reported that concurrent performance of motor and cognitive tasks can be impaired during space missions. Understanding the consequences of HDBR for neural control of dual tasking may possibly provide insight into neural efficiency during spaceflight. In the current study, we evaluated how dual task performance and the underlying brain activation changed as a function of HDBR. Eighteen healthy men participated in this study. They remained continuously in the 6° head-down tilt position for 70 days. Functional MRI for bimanual finger tapping was acquired during both single task and dual task conditions, and repeated at 7 time points pre-, during- and post-HDBR. Another 12 healthy males participated as controls who did not undergo HDBR. A widely distributed network involving the frontal, parietal, cingulate, temporal, and occipital cortices exhibited increased activation for dual tasking and increased activation differences between dual and single task conditions during HDBR relative to pre- or post-HDBR. This HDBR-related brain activation increase for dual tasking implies that more neurocognitive control is needed for dual task execution during HDBR compared to pre- and post-HDBR. We observed a positive correlation between pre-to-post HDBR changes in dual-task cost of reaction time and pre-to-post HDBR change in dual-task cost of brain activation in several cerebral and cerebellar regions. These findings could be predictive of changes in dual task processing during spaceflight.
头低位卧床休息（HDBR）已被用作太空飞行模拟，以在地球上模拟微重力暴露对人体生理、感觉运动功能和认知的影响。先前的研究报告称，在太空任务期间，运动和认知任务的同时执行可能会受到损害。了解HDBR对双重任务神经控制的影响可能有助于深入了解太空飞行期间的神经效率。在本研究中，我们评估了双重任务表现和潜在的大脑激活如何随HDBR而变化。18名健康男性参与了本研究。他们在6°头低位倾斜位置持续保持70天。在单任务和双任务条件下均采集了用于双手手指敲击的功能磁共振成像，并在HDBR前、期间和后的7个时间点重复进行。另外12名健康男性作为未接受HDBR的对照组参与。与HDBR前或后相比，在HDBR期间，一个广泛分布于额叶、顶叶、扣带回、颞叶和枕叶皮质的网络在双重任务时表现出激活增加，并且在双重任务和单任务条件之间的激活差异增加。这种与HDBR相关的双重任务大脑激活增加意味着与HDBR前和后相比，在HDBR期间执行双重任务需要更多的神经认知控制。我们观察到，HDBR前后反应时间双重任务成本的变化与几个大脑和小脑区域中HDBR前后大脑激活双重任务成本的变化之间存在正相关。这些发现可能预测太空飞行期间双重任务处理的变化。
