Howard Hughes Medical Institute, Kavli Institute for Fundamental Neuroscience, Department of Physiology, University of California San Francisco, San Francisco, California.
Hippocampus. 2019 Mar;29(3):184-238. doi: 10.1002/hipo.22956.
Contemporary brain research seeks to understand how cognition is reducible to neural activity. Crucially, much of this effort is guided by a scientific paradigm that views neural activity as essentially driven by external stimuli. In contrast, recent perspectives argue that this paradigm is by itself inadequate and that understanding patterns of activity intrinsic to the brain is needed to explain cognition. Yet, despite this critique, the stimulus-driven paradigm still dominates-possibly because a convincing alternative has not been clear. Here, we review a series of findings suggesting such an alternative. These findings indicate that neural activity in the hippocampus occurs in one of three brain states that have radically different anatomical, physiological, representational, and behavioral correlates, together implying different functional roles in cognition. This three-state framework also indicates that neural representations in the hippocampus follow a surprising pattern of organization at the timescale of ∼1 s or longer. Lastly, beyond the hippocampus, recent breakthroughs indicate three parallel states in the cortex, suggesting shared principles and brain-wide organization of intrinsic neural activity.
当代脑科学研究旨在理解认知如何可简化为神经活动。至关重要的是，这项工作的很大一部分受到一种科学范式的指导，该范式认为神经活动本质上是由外部刺激驱动的。相比之下，最近的观点认为，这种范式本身是不够的，需要了解大脑内在活动的模式，才能解释认知。然而，尽管存在这种批评，刺激驱动的范式仍然占主导地位——可能是因为还没有一个令人信服的替代方案。在这里，我们回顾了一系列的发现，这些发现表明存在这样一种替代方案。这些发现表明，海马体中的神经活动发生在三种大脑状态之一中，这三种状态具有截然不同的解剖学、生理学、表示和行为相关性，共同暗示了在认知中不同的功能作用。这种三态框架还表明，海马体中的神经表示在约 1 秒或更长时间的时间尺度上遵循一种令人惊讶的组织模式。最后，在海马体之外，最近的突破表明皮质中有三个平行的状态，这表明内在神经活动具有共享的原则和全脑组织。
