1. John Hughlings Jackson - Neurologist

John Hughlings Jackson was a prominent British neurologist in the late 19th and early 20th centuries. He is best known for his work on the brain and its functions, particularly regarding epilepsy and the concept of the nervous system's organization. Jackson proposed that the brain is structured in a hierarchical manner, where higher functions depend on lower ones. He also described the phenomenon of "Jacksonian seizures," a specific type of epileptic seizure that starts in one part of the body and can spread. His insights laid foundational principles for modern neuroscience and our understanding of neurological disorders.