Perched recently on a chair in her small office, resplendent in a black satin dress and gold floral pin and banked by moldering towers of old files, she volleyed questions rather than answering them. “People think because I’m 98 years old I must be emerita,” she said. “Well, not at all. I’m still nosy, you know, curious.”
Dr. Milner continues working, because she sees no reason not to. Neither McGill nor the affiliated Montreal Neurological Institute and Hospital has asked her to step aside. She has funding: In 2014 she won three prominent achievement awards, which came with money for research. She has a project: a continuing study to investigate how the healthy brain’s intellectual left hemisphere coordinates with its more aesthetic right one in thinking and memory.
And she has adapted to the life as an undeniably senior senior researcher. “I come into the office about three days a week or so, that is plenty,” Dr. Milner said.
“And I have some rules,” she added. “I will take on postdoctoral students, but not graduate students. Graduate students need to know you’ll be around for five years or so, and well” — she chuckled, looking up at the ceiling — “well, it’s very difficult if they have to switch to someone else, you know.”
Dr. Milner’s current project is, appropriately enough, an attempt to weave together two of brain science’s richest strands of research, both of which she helped originate a lifetime ago.
One is the biology of memory.
Dr. Milner changed the course of brain science for good as a newly minted Ph.D. in the 1950s by identifying the specific brain organ that is crucial to memory formation.
She did so by observing the behavior of a 29-year-old Connecticut man who had recently undergone an operation to relieve severe epileptic seizures. The operation was an experiment: On a hunch, the surgeon suctioned out two trenches of tissue from the man’s brain, one from each of his medial temporal lobes, located deep below the skull about level with the ears. The seizures subsided.
But the patient, an assembly line worker named Henry Molaison, was forever altered. He could no longer form new memories.
Concerned and intrigued, the surgeon contacted Dr. Wilder Penfield and Dr. Milner at the Montreal Neurological Institute, who had previously reported on two cases of amnesia in patients treated there. Thus began a now-famous collaboration.
She started taking the night train from Montreal to give a battery of tests to Mr. Molaison, who was known in research reports as H. M. to protect his privacy.
In a landmark 1957 paper Dr. Milner wrote with Mr. Molaison’s surgeon, she concluded that the medial temporal areas — including, importantly, an organ called the hippocampus — must be critical to memory formation. That finding, though slow to sink in, would upend the accepted teaching at the time, which held that no single area was critical to supporting memory.
Dr. Milner continued to work with Mr. Molaison and later showed that his motor memory was intact: He remembered how to perform certain physical drawing tests, even if he had no memory of learning them.
The finding, reported in 1962, demonstrated that there are at least two systems in the brain for processing memory: one that is explicit and handles names, faces and experiences; and another that is implicit and incorporates skills, like riding a bike or playing a guitar.
“I clearly remember to this day my excitement, sitting there with H. M. and watching this beautiful learning curve develop right there in front of me,” Dr. Milner said. “I knew very well I was witnessing something important.”
The other strand her new research project incorporates is so-called hemispheric specialization: how the brain’s two halves, the right and the left, divide up its mental labor.
In the early 1960s, scientists including Dr. Milner had shown that the brain’s left hemisphere specializes in language and reasoning, and that the right makes holistic, more aesthetic judgments — it is more sensual than intellectual.
Still, in people with brain injuries, particularly to the frontal lobes behind the forehead, the two hemispheres could compensate by working together in subtle ways.
In an era before precise imaging technology, standard pencil-and-paper testing could not easily detect the deficits caused by specific injuries.
In a series of studies, and using the same knack for exhaustive observation, Dr. Milner demonstrated that several kinds of tests could help characterize frontal lobe injuries. One of these, for example, is called the verbal fluency test, which assesses a person’s ability to generate words in certain categories or beginning with certain letters — a test of left hemisphere integrity.
“She didn’t just give the person a test and mark down the score,” Dr. Marilyn Jones-Gotman, a longtime friend and colleague, said. “No, she sat down with people, paid attention to everything they did and said, and wrote it all down. That all went into the record, and gave you clues to what was actually going on in their minds that the scores by themselves couldn’t.”
The new project is aimed at understanding how hemispheric coordination aids memory retrieval under normal circumstances, in people without brain injuries. Dr. Milner leads a research team that has been taking exhaustive M.R.I. brain images from participants while they solve problems and take memory tests.
Does the artistic right hemisphere provide clues to help its more logic-oriented other half retrieve words? If so, which kinds of clues seem most powerful?
In one experiment, participants in the brain scanner tried to recall a list of words they had just studied. Some of those words were concrete, like dog or house, conjuring specific imagery; others, like concept or strategy, were not. The scans carefully track activation across hemispheres moment to moment, as retrieval happens.
“We’re just going through the data from our current study now,” Dr. Milner said, gesturing through the open doorway to Ami Tsuchida, who was working on a computer
For this particular experiment, Dr. Tsuchida said, “We’re looking at the pattern of interactions between left and right hippocampus for words rated as highly imageable relative to those rated as not very imageable” to see if there’s any difference.
The findings hold tremendous potential to help people with early dementia, some brain injuries and even learning disabilities.
“People with early signs of dementia can have trouble with imagery, and by the time the disease is advanced they’ve lost that ability,” said Joelle Crane, a clinical psychologist at the Montreal Neurological Institute. “One area this new work might help us with is in training people to learn in a more visual way.”
For Dr. Milner, after a lifetime exploring the brain, the motive for the work is personal as well as professional. “I live very close; it’s a 10-minute walk up the hill,” she said. “So it gives me a good reason to come in regularly.”
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