现有计算机体系架构下的神经网络难以对多任务复杂数据进行高效处理,成为制约人工智能技术发展的瓶颈之一,而人脑的并行运算方式具有高效率、低功耗和存算一体的特点,被视为打破传统冯·诺依曼计算体系最具潜力的运算体系.突触仿生...现有计算机体系架构下的神经网络难以对多任务复杂数据进行高效处理,成为制约人工智能技术发展的瓶颈之一,而人脑的并行运算方式具有高效率、低功耗和存算一体的特点,被视为打破传统冯·诺依曼计算体系最具潜力的运算体系.突触仿生器件是指从硬件层面上实现人脑神经拟态的器件,它可以模拟脑神经对信息的处理方式,即“记忆”和“信息处理”过程在同一硬件上实现,这对于构建新的运算体系具有重要的意义.近年,制备仿生突触器件的忆阻材料已获得进展,但多聚焦于神经突触功能的模拟,对于时空信息感知和传递的关键研究较为缺乏.本文通过制备一种双层结构忆阻器,实现了突触仿生器件的基本功能包括双脉冲易化和抑制、脉冲时间依赖突触可塑性(spiking time dependent plasticity,STDP)和经验式学习等,还对器件的信息感知、传递特性和稳定性进行了研究,发现该器件脉冲测试结果满足神经网络处理时空信息的基本要求,这一结果可以为忆阻器在类脑芯片中的应用提供参考.展开更多
Aim: Hippocampal long-term potentiation (LTP), an activity-dependent plasticity in synaptic transmission, is believed as a fundamental mechanism of learning and memory. This form of plasticity also exists in spinal do...Aim: Hippocampal long-term potentiation (LTP), an activity-dependent plasticity in synaptic transmission, is believed as a fundamental mechanism of learning and memory. This form of plasticity also exists in spinal dorsal horn. Our previous work showed that electrical as well as natural noxious stimulation of afferent C-fibers or acute injury of the sciatic nerve produces LTP of C-fiber evoked field potentials in spinal dorsal horn.展开更多
Objective To investigate the spike activities of cerebellar cortical cells in a computational network model con- structed based on the anatomical structure of cerebellar cortex. Methods and Results The multicompartmen...Objective To investigate the spike activities of cerebellar cortical cells in a computational network model con- structed based on the anatomical structure of cerebellar cortex. Methods and Results The multicompartment model of neuron and NEURON software were used to study the external influences on cerebellar cortical cells. Various potential spike patterns in these cells were obtained. By analyzing the impacts of different incoming stimuli on the potential spike of Purkinje cell, temporal focusing caused by the granule cell-golgi cell feedback inhibitory loop to Purkinje cell and spa- tial focusing caused by the parallel fiber-basket/stellate cell local inhibitory loop to Purkinje cell were discussed. Finally, the motor learning process of rabbit eye blink conditioned reflex was demonstrated in this model. The simulation results showed that when the afferent from climbing fiber existed, rabbit adaptation to eye blinking gradually became stable under the Spike Timing-Dependent Plasticity （STDP） learning rule. Conclusion The constructed cerebellar cortex network is a reliable and feasible model. The model simulation results confirmed the output signal stability of cerebellar cortex after STDP learning and the network can execute the function of spatial and temporal focusing.展开更多
文摘现有计算机体系架构下的神经网络难以对多任务复杂数据进行高效处理,成为制约人工智能技术发展的瓶颈之一,而人脑的并行运算方式具有高效率、低功耗和存算一体的特点,被视为打破传统冯·诺依曼计算体系最具潜力的运算体系.突触仿生器件是指从硬件层面上实现人脑神经拟态的器件,它可以模拟脑神经对信息的处理方式,即“记忆”和“信息处理”过程在同一硬件上实现,这对于构建新的运算体系具有重要的意义.近年,制备仿生突触器件的忆阻材料已获得进展,但多聚焦于神经突触功能的模拟,对于时空信息感知和传递的关键研究较为缺乏.本文通过制备一种双层结构忆阻器,实现了突触仿生器件的基本功能包括双脉冲易化和抑制、脉冲时间依赖突触可塑性(spiking time dependent plasticity,STDP)和经验式学习等,还对器件的信息感知、传递特性和稳定性进行了研究,发现该器件脉冲测试结果满足神经网络处理时空信息的基本要求,这一结果可以为忆阻器在类脑芯片中的应用提供参考.
文摘Aim: Hippocampal long-term potentiation (LTP), an activity-dependent plasticity in synaptic transmission, is believed as a fundamental mechanism of learning and memory. This form of plasticity also exists in spinal dorsal horn. Our previous work showed that electrical as well as natural noxious stimulation of afferent C-fibers or acute injury of the sciatic nerve produces LTP of C-fiber evoked field potentials in spinal dorsal horn.
基金supported by the grants from National Natural Science Foundation of China (No. 10872069)
文摘Objective To investigate the spike activities of cerebellar cortical cells in a computational network model con- structed based on the anatomical structure of cerebellar cortex. Methods and Results The multicompartment model of neuron and NEURON software were used to study the external influences on cerebellar cortical cells. Various potential spike patterns in these cells were obtained. By analyzing the impacts of different incoming stimuli on the potential spike of Purkinje cell, temporal focusing caused by the granule cell-golgi cell feedback inhibitory loop to Purkinje cell and spa- tial focusing caused by the parallel fiber-basket/stellate cell local inhibitory loop to Purkinje cell were discussed. Finally, the motor learning process of rabbit eye blink conditioned reflex was demonstrated in this model. The simulation results showed that when the afferent from climbing fiber existed, rabbit adaptation to eye blinking gradually became stable under the Spike Timing-Dependent Plasticity （STDP） learning rule. Conclusion The constructed cerebellar cortex network is a reliable and feasible model. The model simulation results confirmed the output signal stability of cerebellar cortex after STDP learning and the network can execute the function of spatial and temporal focusing.
