System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan.
Brain Topogr. 2013 Oct;26(4):591-605. doi: 10.1007/s10548-013-0304-z. Epub 2013 Jun 29.
Previous studies have reported that multiple brain regions are activated during spatial navigation, but it remains unclear how this activation is converted to motor commands for navigation. This study was aimed to investigate synchronization across different brain regions and between cortical areas and muscles during spatial navigation. This synchronization has been suggested to be essential for integrating activity in the multiple brain areas to support higher cognitive functions and for conversion of cortical activity to motor commands. In the present study, the subjects were required to sequentially trace ten checkpoints in a virtual town by manipulating a joystick and to perform this three times while electroencephalograms and electromyograms from the right arm were monitored. Time spent on the task in the third trial was significantly lesser than that in the first trial indicating an improvement in task performance. This repeated learning was associated with an increase in alpha power at the electrodes over the contralateral sensorimotor region and in theta power at the electrodes over the bilateral premotor and frontotemporal regions. Alpha- and theta-range corticocortical coherences between these regions and other brain areas were also increased in the third trial compared to the first trial. Furthermore, alpha- and theta-range corticomuscular coherence was significantly increased in the second and third trials compared to the first trial. These results suggest that alpha- and theta-range synchronous activity across multiple systems is essential for the integrated brain activity required in spatial navigation and for the conversion of this activity to motor commands.
先前的研究报告指出，在空间导航过程中多个脑区被激活，但目前尚不清楚这种激活如何转化为导航的运动指令。本研究旨在探讨空间导航过程中不同脑区之间以及皮质区与肌肉之间的同步性。这种同步性被认为对于整合多个脑区的活动以支持更高的认知功能以及将皮质活动转化为运动指令至关重要。在本研究中，要求被试通过操纵操纵杆依次追踪虚拟城镇中的十个检查点，并在监测到右侧手臂的脑电图和肌电图时重复进行三次。第三次试验中完成任务所花费的时间明显少于第一次试验，表明任务表现有所提高。这种重复学习与对侧感觉运动区电极处的α功率增加以及双侧运动前区和额颞区电极处的θ功率增加有关。与第一次试验相比，第三次试验中这些区域与其他脑区之间的α波和θ波范围皮质皮质相干性也增加了。此外，与第一次试验相比，第二次和第三次试验中的α波和θ波范围皮质肌相干性显著增加。这些结果表明，多个系统之间的α波和θ波范围同步活动对于空间导航中所需的整合脑活动以及将这种活动转化为运动指令至关重要。
