The journey to understand and mimic the brain's architecture began in the early 20th century when scientists first began to comprehend how neurons communicate. Santiago Ramón y Cajal's groundbreaking work in neuroscience revealed that the nervous system consists of discrete cells that communicate through electrical and chemical signals. This discovery laid the foundation for what would eventually become the field of artificial neural networks.
In 1943, Warren McCulloch and Walter Pitts published a seminal paper titled "A Logical Calculus of the Ideas Immanent in Nervous Activity," which introduced the first mathematical model of an artificial neuron. Their model, though simplified compared to biological neurons, captured the essential concept of how neurons receive inputs, process them, and produce outputs. This mathematical abstraction became the building block for all future neural network architectures.