Nanoelektronik, Technische Fakultät, Christian-Albrechts-Universität zu Kiel, Kiel 24143, Germany.
Sci Adv. 2017 Oct 25;3(10):e1700849. doi: 10.1126/sciadv.1700849. eCollection 2017 Oct.
The human brain is able to integrate a myriad of information in an enormous and massively parallel network of neurons that are divided into functionally specialized regions such as the visual cortex, auditory cortex, or dorsolateral prefrontal cortex. Each of these regions participates as a context-dependent, self-organized, and transient subnetwork, which is shifted by changes in attention every 0.5 to 2 s. This leads to one of the most puzzling issues in cognitive neuroscience, well known as the "binding problem." The concept of neural synchronization tries to explain the problem by encoding information using coherent states, which temporally patterns neural activity. We show that memristive devices, that is, a two-terminal variable resistor that changes its resistance depending on the previous charge flow, allow a new degree of freedom for this concept: a local memory that supports transient connectivity patterns in oscillator networks. On the basis of the probability distribution of the resistance switching process of Ag-doped titanium dioxide memristive devices, a local plasticity model is proposed, which causes an autonomous phase and frequency locking in an oscillator network. To illustrate the performance of the proposed computing paradigm, the temporal binding problem is investigated in a network of memristively coupled self-sustained van der Pol oscillators. We show evidence that the implemented network allows achievement of the transition from asynchronous to multiple synchronous states, which opens a new pathway toward the construction of cognitive electronics.
人类大脑能够在神经元的巨大而大规模并行网络中整合无数信息,这些神经元被分为功能专门化的区域,如视觉皮层、听觉皮层或背外侧前额叶皮层。这些区域中的每一个都作为一个上下文相关的、自我组织的、瞬态子网参与其中,注意力的变化每 0.5 到 2 秒就会改变这个子网。这导致了认知神经科学中最令人困惑的问题之一,即“绑定问题”。神经同步的概念试图通过使用相干态来编码信息来解释这个问题,这种相干态可以对神经活动进行时间模式化。我们表明,忆阻器设备,即一种两端可变电阻器,其电阻会根据之前的电荷流动而改变,为这个概念提供了一个新的自由度:一种支持振荡器网络中瞬态连接模式的局部记忆。基于掺银二氧化钛忆阻器设备的电阻切换过程的概率分布,提出了一种局部可塑性模型,该模型导致振荡器网络中的自主相位和频率锁定。为了说明所提出的计算范例的性能,研究了在忆阻耦合自维持范德波尔振荡器网络中的时间绑定问题。我们证明,所实现的网络允许实现从异步到多个同步状态的转变,这为构建认知电子学开辟了一条新途径。