Answer: Brenda Milner is most famous for developing the field of neuropsychology, the study of the brain and behavior.
From https://www.mcgill.ca/reporter/40/08/milner/
Dr. Brenda Milner’s research is mainly centered around the deficits of the brain after an injury or surgery. She is also very interested in studying the lateralization of the brain, or how the two hemispheres have different functions.
Early in her career, she worked with several other highly esteemed neuroscientists, including Donald Hebb and Wilder Penfield.
She worked closely with Patient HM (Henry Molaison), the man with profound amnesia as a result of a surgical removal of his temporal lobes. Through her work with Henry, she helped expand our understanding of the importance of temporal lobe structures such as the hippocampus in memory.
She is currently a professor at McGill University in the Department of Neurology and Neurosurgery. She also does research in understanding the roles of the hemispheric preference of language lateralization in ambidextrous individuals.