Fig. 18From: Recent Advances on Neuromorphic Systems Using Phase-Change MaterialsFour types of the STDP characteristics obtained from the c-GST-based electronic synapse. a Antisymmetric Hebbian learning rule. b Antisymmetric anti-Hebbian learning rule. c Symmetric Hebbian learning rule. d Symmetric anti-Hebbian learning rule. Reprinted with permission from [103]Back to article page