Jadaun Priyamvada, Cui Can, Liu Sam, Incorvia Jean Anne C
Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
Microelectronics Research Center, The University of Texas at Austin, Austin, TX 78758, USA.
PNAS Nexus. 2022 Sep 29;1(5):pgac206. doi: 10.1093/pnasnexus/pgac206. eCollection 2022 Nov.
Neuromorphic computing mimics the organizational principles of the brain in its quest to replicate the brain's intellectual abilities. An impressive ability of the brain is its adaptive intelligence, which allows the brain to regulate its functions "on the fly" to cope with myriad and ever-changing situations. In particular, the brain displays three adaptive and advanced intelligence abilities of context-awareness, cross frequency coupling, and feature binding. To mimic these adaptive cognitive abilities, we design and simulate a novel, hardware-based adaptive oscillatory neuron using a lattice of magnetic skyrmions. Charge current fed to the neuron reconfigures the skyrmion lattice, thereby modulating the neuron's state, its dynamics and its transfer function "on the fly." This adaptive neuron is used to demonstrate the three cognitive abilities, of which context-awareness and cross-frequency coupling have not been previously realized in hardware neurons. Additionally, the neuron is used to construct an adaptive artificial neural network (ANN) and perform context-aware diagnosis of breast cancer. Simulations show that the adaptive ANN diagnoses cancer with higher accuracy while learning faster and using a more compact and energy-efficient network than a nonadaptive ANN. The work further describes how hardware-based adaptive neurons can mitigate several critical challenges facing contemporary ANNs. Modern ANNs require large amounts of training data, energy, and chip area, and are highly task-specific; conversely, hardware-based ANNs built with adaptive neurons show faster learning, compact architectures, energy-efficiency, fault-tolerance, and can lead to the realization of broader artificial intelligence.
神经形态计算在试图复制大脑智力能力的过程中模仿大脑的组织原理。大脑令人印象深刻的能力之一是其自适应智能,这使大脑能够“即时”调节其功能,以应对无数不断变化的情况。特别是,大脑展现出三种自适应且先进的智能能力,即情境感知、交叉频率耦合和特征绑定。为了模仿这些自适应认知能力,我们使用磁斯格明子晶格设计并模拟了一种新型的基于硬件的自适应振荡神经元。馈入神经元的充电电流会重新配置斯格明子晶格,从而“即时”调节神经元的状态、其动力学以及传递函数。这种自适应神经元用于展示这三种认知能力,其中情境感知和交叉频率耦合此前尚未在硬件神经元中实现。此外,该神经元用于构建一个自适应人工神经网络(ANN)并对乳腺癌进行情境感知诊断。模拟结果表明,与非自适应ANN相比,自适应ANN在诊断癌症时具有更高的准确率,同时学习速度更快,且使用的网络更紧凑、更节能。这项工作进一步描述了基于硬件的自适应神经元如何能够缓解当代ANN面临的几个关键挑战。现代ANN需要大量的训练数据、能量和芯片面积,并且高度依赖特定任务;相反,用自适应神经元构建的基于硬件的ANN显示出更快的学习速度、紧凑的架构、能源效率、容错能力,并且能够促成更广泛人工智能的实现。