Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, United Kingdom.
Department of Experimental Psychology, University of Oxford, United Kingdom; Oxford Centre for Human Brain Activity, University of Oxford, United Kingdom.
Neurosci Biobehav Rev. 2019 Jun;101:1-12. doi: 10.1016/j.neubiorev.2019.03.017. Epub 2019 Mar 26.
Working memory, the ability to keep recently accessed information available for immediate manipulation, has been proposed to rely on two mechanisms that appear difficult to reconcile: self-sustained neural firing, or the opposite-activity-silent synaptic traces. Here we review and contrast models of these two mechanisms, and then show that both phenomena can co-exist within a unified system in which neurons hold information in both activity and synapses. Rapid plasticity in flexibly-coding neurons allows features to be bound together into objects, with an important emergent property being the focus of attention. One memory item is held by persistent activity in an attended or "focused" state, and is thus remembered better than other items. Other, previously attended items can remain in memory but in the background, encoded in activity-silent synaptic traces. This dual functional architecture provides a unified common mechanism accounting for a diversity of perplexing attention and memory effects that have been hitherto difficult to explain in a single theoretical framework.
工作记忆是一种能够将最近获取的信息保持在可立即操作状态的能力，它被认为依赖于两种似乎难以协调的机制：自我维持的神经放电，或相反的-活动沉默的突触痕迹。在这里，我们回顾和对比了这两种机制的模型，然后表明，这两种现象可以在一个统一的系统中共存，在这个系统中，神经元在活动和突触中存储信息。灵活编码神经元的快速可塑性允许将特征绑定在一起形成对象，一个重要的新兴特性是注意力的焦点。一个记忆项目通过在被关注或“聚焦”的状态下持续的活动来保持，因此比其他项目记得更好。其他以前被关注的项目可以保留在记忆中，但处于背景中，以活动沉默的突触痕迹编码。这种双重功能架构提供了一个统一的共同机制，解释了许多令人困惑的注意力和记忆效应，这些效应在单一理论框架中迄今难以解释。
