大脑行动网络

作为复杂系统, 大脑始终以一个功能整体在运行, 并由多个脑网络共同完成内在系统和外界环境的交互. 一 方面, 在没有特定外源性任务的静息状态, 大脑仍保持有组织的内源性自发神经活动并维持网络内各区域功能同步. 以往脑影像研究发现, 有一组脑区在静息状态时保持相对高能耗, 在面对各类任务刺激时总是表现出非任务依赖性 负激活, 这些脑区的脑活动高度同步, 组成一个功能网络, 称为默认网络. 另一方面, 大脑在执行特定目标导向的外 在任务时, 表现出高觉醒水平、注意力聚焦、并产生行动计划等认知特征. 最新的脑影像研究发现, 在这种任务行 动状态时, 脑内也有一组脑区在面对各类任务刺激时表现出非任务依赖的正激活, 形成一个功能网络, 称为行动网 络. 从脑的工作原理机制来看, 默认网络与行动网络是互为对应并组成大脑复杂动力学系统的“阴”“阳”两极. 行动网 络的发现不仅深化而且完备了对人脑工作原理的理解, 更为脑疾病的机制研究乃至类脑智能的开发提供了新视角. 本文首先回顾了默认网络的命名历程, 探讨行动网络的命名; 其次, 综述了行动网络的发现过程和脑成像证据, 解 析其脑区解剖构成和功能特征; 并基于临床视角提出了行动网络脑区解剖构成的三维分层观点(皮层-基底节/丘脑小脑), 建议未来研究应从皮层、基底节/丘脑和小脑三个维度整合考量, 为神经科学临床和基础研究提供系统框架. 再次, 文章阐述了行动网络和默认网络的功能对立统一理论洞见, 强调未来应对行动网络解剖和功能的网络神经科 学规律、全生命周期发展与演化的神经机制进行深入研究, 创新多层次、多学科的交叉科学范式, 揭示其脑成像发 现的跨尺度神经生理机制. 最后, 本文展望了大脑行动网络对于脑科学与类脑研究的重要科学意义和应用价值.

As a complex system, the brain always operates as a functional whole, with multiple brain networks collectively facilitating the interaction between the intrinsic system and the external environment. On one hand, in the resting state without specific tasks, the brain maintains organized intrinsic neural activity and synchronizes the functions of different regions within the networks. Previous neuroimaging studies have identified a set of brain regions that exhibit relatively high energy consumption in the resting state and consistently show non-task-dependent negative activation in response to various task stimuli. The neural activities in these brain regions are highly synchronized, forming a functional network known as the default network (DN). On the other hand, when the brain is engaged in high-load, goal-oriented external tasks, it exhibits cognitive characteristics such as high arousal levels, focused attention, and the generation of action plans. The latest neuroimaging research has revealed that in this task-action state, there is also a set of brain regions that show non-taskdependent positive activation in response to various task stimuli, forming a functional network termed the action network (AN). From the perspective of working mechanism, the DN and the AN are complementary and constitute the “yin” and “yang” poles of the brain’s complex dynamical system. The discovery of the AN not only deepens and completes our understanding of the brain’s working principles but also provides a new perspective for the study of brain disease mechanisms and the development of brain-inspired intelligence. This paper first reviews the naming process of the DN and explores the naming of the AN. It then summarizes the discovery process and neuroimaging evidence of the AN, analyzes its anatomical composition and functional characteristics, and proposes a three-dimensional hierarchical view of the AN’s anatomical structure from a clinical perspective (cortex-basal ganglia/thalamus-cerebellum). It is suggested that future research should integrate considerations from the three dimensions of cortex, basal ganglia/thalamus, and cerebellum to provide a systematic framework for clinical and basic research in neuroscience. Thirdly, the paper elaborates on the theoretical insight into the functional opposition and unity of the AN and the DN, emphasizing the need for future in-depth studies on the network neuroscience laws of the AN’s anatomy and function, its development and evolution across the entire life span, and the innovation of multi-level, interdisciplinary scientific paradigms to reveal the cross-scale neurophysiological mechanisms underlying its neuroimaging findings. Finally, the paper looks forward to the important scientific significance and application value of the brain’s AN for brain science and brain-inspired research.