Two scientists, Warren S. McCulloch and Walter H. Pitts, publish the groundbreaking paper A Logical Calculus of the Ideas Immanent in Nervous Activity. The paper quickly became a foundational work in the study of artificial neural networks and has many applications in artificial intelligence research. In it McCulloch and Pitts described a simplified neural network architecture for intelligence, and while the neurons they described were greatly simplified compared to biological neurons, the model they proposed was enhanced and improved upon by subsequent generations of researchers.