If you’ve ever wondered where your memory has gone, ask Brenda Milner. The British-Canadian, who just turned 100, was one of the first researchers to discover how memories are stashed in the brain. Having spent the last 68 years investigating how we consolidate new knowledge, you could say that she knows a thing or two about remembering.
Dr. Milner began her career as one of a handful of women admitted to study mathematics at Cambridge University in 1936. Her determination was evident even then. “Cambridge was associated with mathematics and physics—you know Isaac Newton went there. That’s where I wanted to go and nowhere else,” she told me in 2007 (I recently interviewed her again by email).
This tenacity served Dr. Milner well when she moved from crunching numbers at the British Defense Ministry to Montreal in 1944, to pursue a Ph.D. in psychology. There she worked with the neurologist Wilder Penfield at McGill’s Montreal Neurological Institute. Their research on the post-surgical brain function of epileptic patients led her to reject the then-fashionable theories that memory was a product of Freudian urges or behaviorist stimulus-response chains. Her key insight was to see memory as a feature of human neurobiology.
Dr. Milner is now considered one of the founders of cognitive neuroscience, which links the mind—perceiving, thinking, remembering—to the brain. One of the current leaders in the field, Michael Gazzaniga of the University of California, Santa Barbara, calls her “a true pioneer.”
When she started in the 1950s, the only way to localize mental activity was to see what had changed after injuries or surgery. One patient was Henry Molaison, a 24-year-old from Connecticut who suffered from debilitating epilepsy. H.M., as he was known until his death in 2008, underwent surgery to remove parts of his temporal lobe—including his hippocampus—which the doctors thought to be the locus of his seizures.
Dr. Milner tested his cognitive function after surgery and in a 1957 paper described what happened next. Though H.M.’s personality and intelligence seemed unchanged “there has been one striking and totally unexpected behavioral result: a grave loss of recent memory. After the operation this young man could no longer recognize the hospital staff nor find his way to the bathroom.” H.M. remembered events from his distant past and with practice could learn new motor skills, but without his hippocampus, any novel experience—who he just met or what he ate for lunch—never jelled into a long-term memory.
H.M. was forced to live in the present, which despite its Zen billing, had its downsides. He had to learn of his father’s death over and over again. Each time he grieved anew. Ultimately he kept a reminder in his pocket as a form of self-protection.
By showing how distinct types of memory are stored in different brain systems—how to ride a bike or sing a Broadway tune is stored differently than the name of your third-grade teacher—Dr. Milner revamped neuroscience’s atlas of memory. Knowing how to do something does not require the hippocampus. Knowing that you’ve learned something does.
Dr. Milner still goes to the lab a few days a week. Though most people associate her with H.M., she is “more excited about my frontal lobe work,” which helped to define the seat of self-control, planning and decision-making.
“Brain imaging is a huge thing,” she said in a recent email, when I asked what had changed in 60 years. “Back then, you had to wait until the subject died because the only way to see the brain was to dissect it.” Now you can assess healthy young adults. “To see the brain images of a living person while testing them is extremely exciting.” After all, she added, “we all go downhill after our mid-40s.”
Clearly, Brenda Milner is the ultimate exception to that rule.