Wilhelm Lenz Ernst Ising Ising model recurrent neural network Shun'ichi Amari John Hopfield McCulloch Pitts threshold logic artificial intelligence
Wilhelm Lenz (1920) and Ernst Ising (1925) created and analyzed the Ising model which is essentially a non-learning artificial recurrent neural network (RNN) consisting of neuron-like threshold elements. In 1972, Shun'ichi Amari made this architecture adaptive. His learning RNN was popularised by John Hopfield in 1982.
McCulloch and Pitts  (1943) also created a computational model for neural networks based on mathematics and algorithms. They called this model threshold logic. These early models paved the way for neural network research to split into two distinct approaches. One approach focused on biological processes in the brain and the other focused on the application of neural networks to artificial intelligence.
