REPRESENTATION OF TIME IN THE BRAIN

据了解，大脑可以解决两个刺激的顺序，在时间上分开了少至30毫秒，但是，很少有共识，如何以及在哪里这样的歧视。为了阐明大脑如何对感觉信号进行排序，我们对人类和动物进行了一系列实验。1）我们以前报道过，两个连续刺激的时间顺序判断，传递到每只手持有的棍棒的尖端，通过交叉棍棒而不改变手的位置来改变。以前的报告提供了证据，触觉信号的转介到一个实际的工具在手中的尖端。在这项研究中，我们研究了是否发生转介的提示，或行动点，虚拟工具的操作对象在虚拟现实中的反作用力。结果表明，体感信号可以被称为虚拟工具的动作点，没有任何刚体连接的动作点和手。2）阐明 ...更多信息 为了了解感觉信号在大脑中的顺序，研究人员使用了事件相关功能磁共振成像（fMRI），同时右手受试者判断两个连续刺激的时间顺序。在时间顺序判断时，双侧颞中回后部（BA 37）、双侧运动前区（BA 6）、双侧额下回（BA 44）、双侧顶叶下区（BA 40）以及左侧初级和次级躯体感觉皮层的激活程度高于数字判断时。颞中回的激活与MT/V5的前部重叠。3）为了研究体感刺激在小鼠大脑中如何排序，在C57 BL/6 N小鼠中检查了c-Fos的产生，这些小鼠被训练来判断传递到右侧和左侧胡须的两个喷气刺激的顺序。与对照组相比，任务组的初级体感皮层（桶皮层）、丘脑室旁核、下丘脑和压后无颗粒皮层的c-Fos表达双侧增强。c-Fos在桶皮质中的表达在胼胝体纤维起源的第II层和第III层中最明显。两者合计，我们推断，触觉信号的时间顺序是有序的时间相结合的代表性的“运动”在颞多模态区域与空间表示的刺激在额叶和顶叶皮层。少

It is known that the brain can resolve the order of two stimuli that are separated in time by as little as 30 ms. However, there is little consensus on how and where such discriminations are made. To elucidate how the brain orders sensory signals, we carried out a series of experiments with human and animal subjects. 1)We previously reported that temporal order judgment of two successive stimuli, delivered to the tips of sticks held in each hand, was altered by crossing the sticks without changing the positions of the hands. The previous report provided evidence for the referral of tactile signals to the tip of an actual tool in hand. In this study, we examined whether the referral occur to the tip, or action point, of a virtual tool for manipulating objects in the virtual reality with reaction force. The results suggest that somatosensory signals can be referred to the action point of a virtual tool that lacks any rigid body connecting the action point and the hand. 2)To elucidate whe … More re and how sensory signals are ordered in the brain, event-related functional magnetic resonance imaging (fMRI) was used while right-handed subjects judged the temporal order of two successive stimuli delivered one to each hand. Greater activation was elicited during the temporal order judgment than during the numerosity judgment in the following areas : bilateral posterior part of the middle temporal gyri (BA 37), bilateral premotor cortices (BA 6), bilateral inferior frontal gyri (BA 44), bilateral inferior parietal cortices (BA 40), and the left primary and secondary somatosensory cortices. The activation in the middle temporal gyri overlapped with the anterior part of the MT/V5.3) To study how somatosensory stimuli are ordered in the mouse brain, c-Fos production was examined in C57BL/6N mice that were trained to judge the order of two air-puff stimuli that were delivered to the right and the left whiskers. c-Fos expression was enhanced bilaterally in the task group as compared to the control group in the primary somatosensory cortex (barrel cortex), the paraventricular thalamic nucleus, the hypothalamus and the retrosplenial agranular cortex. c-Fos expression in the barrel cortex was most evident in the layers II and III, where callosal fibers originate from. Taken together, we infer that temporal order of tactile signals are ordered in time by combining representation of 'motion' in the temporal multimodal areas with the spatial representation of the stimuli in the frontal and parietal cortices. Less