Brenda Milner
July 15, 1918 — Manchester, England
Brenda Milner is a British-Canadian neuropsychologist who, through her decades-long study of patients with brain injuries — most famously the amnesiac known as H.M. — established the fundamental principles of how the human brain creates, stores, and retrieves memories, making her one of the most consequential scientists of the twentieth century.
Cambridge to Montreal
Born on July 15, 1918 in Manchester, England, Milner studied experimental psychology at the University of Cambridge, where she was taught by Frederic Bartlett, one of the early giants of cognitive psychology. After the Second World War, during which she taught radar operation to members of the Royal Canadian Air Force, she emigrated to Canada and joined the newly formed Montreal Neurological Institute (MNI) under the neurosurgeon Wilder Penfield — himself one of the most important figures in the history of brain surgery. At McGill University, she began the systematic psychological testing of Penfield's patients, developing new methods for understanding what different brain regions actually do by carefully studying what happens when they are damaged or surgically removed.
Patient H.M. and the Discovery of Memory Systems
In 1955, Milner began studying Henry Molaison (known during his lifetime only as H.M. to protect his privacy), a young man who had undergone surgery to treat severe epilepsy and emerged from the operation with a profound, permanent inability to form new long-term memories. He could remember his childhood clearly and could hold a thought for about 30 seconds, but could not transfer new information into lasting memory. What Milner discovered through years of careful testing transformed neuroscience: she demonstrated that memory is not a single system housed in a single place, but a collection of distinct systems in distinct brain areas. Most strikingly, she found that H.M. could learn new motor skills — tasks requiring procedural memory, like mirror-tracing — even though he had no conscious memory of ever having practised them. This proved that different types of memory are processed in different brain structures. Her work with H.M. established the hippocampus as central to the formation of episodic and declarative memory, a finding that reshaped neuroscience, psychiatry, and psychology.
Did You Know?
Every time Milner walked into the room to test H.M., he had no recollection of ever having met her, despite the fact that she had been testing him for years. He was always polite and cooperative; he simply had no access to any record of their previous meetings. Yet when she asked him to trace a star shape while looking in a mirror — a difficult task — his performance improved each day he tried it, even though each day he believed he had never done it before. This dissociation between knowing how to do something and knowing that you have done it was one of the most striking findings in the history of brain science.
A Century of Science
Milner has continued to work at the Montreal Neurological Institute into her 100s, holding the position of Professor of Neurology and Neurosurgery at McGill University. She has received honorary degrees from more than twenty universities and has been awarded the Gairdner International Award, the Kavli Prize, the Balzan Prize, the Patroness Medal of the Royal Society of Canada, and the Order of Canada. She became a Companion of the Order of Canada in 2004. She has never retired. Her career — spanning more than seven decades of active research — is itself a remarkable fact. She is widely regarded not merely as one of the greatest neuroscientists who has ever lived, but as the founder of human neuropsychology as a scientific discipline.