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  • Writer's pictureDale DeBakcsy

Building a Kingdom in the Brain’s Unfashionable District: Brenda Milner’s Century of Neuropsychology

There are scales and metrics you use to evaluate the lives of most neuropsychologists, and then there are those you have to invent in order to speak with any degree of justice about people like Brenda Milner.


She was born in 1918, four months before the end of World War I.


She earned her BA degree in 1939, on the eve of Europe plunging headlong into World War II.


Her masterful study of the role of the hippocampus for memory consolidation was published in 1957, the year that the Soviet Union launched Sputnik into space.


Her major study of speech lateralization was published in 1977, as movie-goers flocked to see Star Wars in the theater.


Her studies of brain imaging during tone perception for Chinese and English speakers were released in 2001, as the world changed in the wake of the World Trade Center attacks.


And when this book is published, if the world decides, just this once, to be just, she will be but a few months away from her 106th birthday.


How much the world has changed over the course of Milner’s life is just barely within the realm of comprehension, but what is more amazing still, is how much she contributed to that change, pushing our knowledge of the brain and memory forward by leaps and flashes, decade after decade, resolutely refusing to stem the tide of her discovery even as she entered the eighth, ninth, and tenth decades of her life.


She was born Brenda Langford, the daughter of two musicians, on July 15, 1918. Because her father was a music critic and pianist, it left him time during the day to spend with her, and up until his death when she was seven years old, he took her education into his own hands, teaching her mathematics, German, and the arts. It was clear from a relatively early point, however, that she was not to be a musician like her parents, though she did seem to have a gift for literature and languages, which her teachers at school encouraged her to develop. She was more interested, however, in physics and mathematics, and, against all advice, decided to attend Cambridge to study the latter, matriculating in 1936.


As often happens with mathematics students, however, once she began her course of study she realized that there is a difference between loving mathematics, and being the sort of person who wants to be a mathematician as their career. She did not, however, want to switch back to humanities, believing that one could always study humanities independently on the side throughout one’s life, but that science, once given up, is more or less gone for good, as to really do science means being part of a research team in a way that being a poet generally doesn’t. She thought about switching to philosophy so she could study logic, which is close kin to mathematics, but her advisors at Cambridge assured her that a philosophy degree was effectively a receipt for unemployment, but that psychology might scratch a similar intellectual itch.


Importantly for her future work, Cambridge, unlike many British higher institutions at the time, was doing work with the connection between psychology and neuroscience comparable to that being done in North America, and Milner had the chance to work with Oliver Zangwill (1913-1987), who was interested in brain lateralisation (i.e. in brain functions that are more heavily associated with one hemisphere of the brain than the other) and the effect of brain lesions on brain functions. She received her BA in experimental psychology in 1939, and secured a scholarship to remain at Cambridge for graduate studies when World War II broke out, and her skills as a psychologist were recruited for the war effort. Like many psychologists in this volume during World War II, she was initially detailed to develop aptitude tests for armed services personnel selection, particularly with creating tests that would distinguish prospective bomber and fighter pilots. Eventually, however, she found her way to radar research, where she focused on the effects of different display types on radar operators.



It was while doing radar research that she met a young electrical engineer, Peter Milner (1919-2018). The pair hit it off, and when, in 1944, he was set to be transferred to Canada to help in the development of Canada’s nuclear program, he proposed to Brenda, who was about to return to her Cambridge graduate studies, but decided to accept his offer instead and move with him to Canada, where her destiny awaited her.


Of course, destiny doesn’t happen all at once, and her immediate concern on arriving in Canada was finding a job that used her skill set to at least some degree, and for seven years she taught animal behavior and experimental psychology at the University of Montreal. It was good work but, she realized, if she wanted to get back in the game of research in North America, she would need a PhD, and applied to McGill University, where she hoped to work under Donald Hebb (1904-1985), who had just published his landmark The Organization of Behavior in 1949. That book gave to the world Hebb’s Postulate, stating that the connections between neurons are made more efficient the more that they fire together, and was a pioneering text in neuropsychology, i.e. the attempt to explain psychological phenomenon with reference to underlying neural structures and reactions.


Hebb’s work stood out in a psychological landscape still very much in the throes of a behaviorism which viewed with great suspicion any attempt to relate outwardly recordable behavior to inner mental or neural states, but Milner was fascinated by the work he was doing, and promised him that, if he took her on as a PhD student, she would see the work through, and not abandon it at the whim of her husband or the vicissitudes of his career. Soon after starting at McGill, however, Hebb received a request from Wilder Penfield at the Montreal Neurological Institute (or “The Neuro”) for a student to help him analyze his surgical patients, and Hebb put Milner’s name forward.


Penfield, who students of psychology will recognize from the “Penfield Diagrams” that depict, via a large-handed, large-mouthed human figure draped over the brain, the relative motor cortex spaced devoted to different parts of the body, and that are featured in virtually every introductory psychology textbook, was a masterful neurosurgeon who employed direct probing of the brain and EEG technology to hone precisely in on which parts of the brain he could safely remove without affecting the patients’ quality of life. He needed Milner to study patients upon whom he performed unilateral medial temporal removals. His research had shown that these were regions of the brain most active during epileptic seizures, and that careful removal of part of the medial temporal lobe most involved in seizures (we have two, one on each side) could vastly reduce epileptic episodes for his patients. He was, however, cautious, and brought Milner on to exhaustively test patients before and after the procedure to determine what other effects the surgery might have produced.



At first, it was rather dull work. Penfield was careful only ever to remove one of the medial temporal lobes, so that the other one could compensate for any loss of function. As such, the patients Milner interviewed all seemed to be doing just fine, with improvements to their symptoms and no other loss of function. Then, one day, she gave a memory test to a patient known in the literature as PB. The test involved patients’ ability to recall details of short stories read to them. PB usually started well, but his accounts lost cohesion as he went along, and when asked a short time later about the same stories, he couldn’t even recall having been read anything at all.


Something was definitely amiss, and when a second patient, FC, turned up with similar memory problems, Milner and Penfield began to hypothesize about what the underlying issue might be. According to the most advanced theories of the time, memory was a global phenomenon in the brain, something spread uniformly through its structure, not localized to a single location. How could the removal of such a tiny section, then, produce such intense results, of individuals unable to form new memories? All the pair could do at that moment was theorize. They believed that both patients had happened to have damage to the other, non-operated-upon, temporal lobe, either through stroke or some congenital defect, and that, as a result, when their remaining good lobe was removed, they lost completely whatever ability lies in the temporal lobes, which, apparently, was the ability to solidify experiences into long-term memory.


Lacking our modern era’s imaging capacities, however, they could not prove their assertions until Penfield happened to run into WB Scoville at a conference. Scoville worked primarily with psychotic patients, whose symptoms and behavioral problems he often treated with bilateral temporal lobectomies, i.e. with removal of both temporal lobes. Scoville shared with Penfield that his patients were suffering severe memory problems, and readily accepted Penfield’s request to have Milner perform her memory tests with those patients who had undergone the procedure. Most of those patients were psychotic, and therefore difficult to examine with anything like certainty as to the origin of their problems, but one, HM, was an individual who had suffered from extreme epileptic episodes his whole life in spite of heavy medication, and had elected for Penfield’s procedure as a desperate last measure to give himself some manner of normalcy.


Twenty nine years old, affable, psychologically “normal”, and with a measured IQ of 118, HM was an ideal research candidate. For decades, he reigned as a superstar in psychological circles, with researchers vying for time with him, as an example of a “pure” injury to both medial temporal lobes not likely to ever come again. What Milner gathered from HM, and from Scoville’s psychopathic patients, was that damage to the hippocampus hindered a person’s ability to form long-term memories, and the worse the damage, the greater the hindrance. She and Scoville collaborated on writing up these results in their 1957 paper, “Loss of Recent Memory After Bilateral Hippocampal Lesions,” which has just recently crossed the 10,000 citations threshold, ranking as one of the most cited and important papers in the history of neuropsychology.


Shortly after having revolutionized neuroscience with the discovery that memory consolidation is regionally located in the brain, and not globally distributed, Milner pulled off a second revolution after giving HM a new test, which involved tracing a star in a mirror. The expectation was that he would get better and better at the task, then lose all of his memory of how to do it, like he lost memory of everything else, and on the next day perform as well as he did when he first received it. What Milner found, however, was that, given the task the next day, though he did not remember ever having seen it before, he was, somewhat to his amazement, performing as well as he was at the end of the previous day, and after three days was performing it perfectly. He had remembered how to do the task, even though he didn’t remember ever learning to do it. The implication was staggering: the brain possesses different ways for processing and storing different types of memory, what we now think of as implicit and explicit memory systems, with damage to the centers responsible for the one still allowing the other to take place normally.



Milner’s studies of memory were so far-reaching in their impact, so unexpected in their conclusions, that some historians give them credit for putting cognitive neuroscience on the map as a respectable field of study, at a stroke saving the discipline from the years of disdain heaped on it from the behaviorist camp. For her part, Milner would continue checking in on HM through the 1960s, but by the 1970s had largely handed that role over to MIT, where Suzanne Corkin (whom we shall meet in more detail soon) would continue the work she had begun so spectacularly. Milner, meanwhile, was on to the next thing, which was her study of the frontal lobe. In her words, “When I first arrived at the Neuro, the frontal lobes were being debunked and were wildly unfashionable.” The studies that had been done on them were of poor quality, and tended towards the conclusion that this region of the brain didn’t do anything particularly important.


Milner suspected otherwise, particularly in the light of research being done at the University of Wisconsin on frontal lesions in monkeys. She decided to import one of the tests being developed there to the Neuro, and try them out on humans with frontal lobe lesions. This was the Wisconsin Card Sorting Test, first developed in 1948. This involves giving subjects cards to sort, which have one of four different ways that they can be sorted (based on color, symbol shape, etc.). The examiner only tells the subject if they have sorted a card correctly or not, leaving them to figure out what the rule is. The trick comes with the fact that, at every tenth card, the examiner changes which sorting rule the subjects need to employ to get “correct” answers. Milner found that patients with frontal lobe lesioning had a much harder time than control subjects in switching to new rules, evincing a deficit in their ability to reverse previous learning, resulting in characteristic problem solving rigidity. She published her results in “Effects of Different Brain Lesions on Card Sorting: The Role of the Frontal Lobes” (1963), which has been cited some 3300 times since, and which was an early step in the rehabilitation of the Frontal Lobe which we are now very much in the midst of.


Again, Milner could have kept riding the new interest she had created in the frontal lobes, just as she could have kept riding the interest she had stoked for the temporal lobes a decade earlier, but though she kept updating her previous work (writing about frontal lobe lesions and their impact on cognitive and behavioral functions in 1982 and 1984, respectively, and updating the world on HM’s amnesiac syndrome in 1968) she also kept pressing forward into new fields of interest, including the lateralization of language and handedness with interesting results on how early lesions to the left hemisphere can cause redistribution of faculties between the hemispheres (1977), and imaging studies of bilingual brains performing word generation tasks aimed at discovering whether second languages are stored in the brain differently from how primary languages are (1995) and at how general tone perception differs between speakers of tone-based languages (like Chinese) and non tone-based ones (like English) (2001). She continued teaching, advising, and researching past her one hundredth birthday, which was celebrated by the psychological community in 2018 with a symposium featuring an appreciation of her ten decades of life and seven decades of pioneering neuroscientific work. She consistently ranks “curiosity” as the number one trait that she looks for in graduate students, and credits it as the quality that has kept her pushing forward, never resting on her abundant laurels, but instead always thrusting her nose around the next corner, spending the long life she has been given in the acts of Noticing and Inquiring, of finding those pieces that don’t quite fit the neurological structures as we know them, and excitedly devising ways to plumb the contradictions at large. One curious brain has been the gateway through which we have learned about all our brains, as they move through life attempting to observe, learn, and remember.


FURTHER READING:


Because of her longevity and importance, we are fortunate to have a number of in-depth interviews with Milner where she reflects, with an accuracy and precision at 90 years of age that I have never possessed in my entire life, on the course of her career, the people she worked with, and the challenges she faced, studying against all counsel those parts of the brain deemed unimportant by other scientists, and striving, against vociferous opinions that it was a waste of time, to bring psychology and neuroscience into closer connection. For her and Penfield’s part in studying HM, you can pick up Luke Dittrich’s Patient H.M. (2017), with the caveat that, when it’s good, the book is very good, and when it isn’t, it very isn’t. The parts about Milner and Penfield are among the best, and are based on interviews with Milner, but I wouldn’t recommend it as a good source about Suzanne Corkin, for reasons we’ll get into in her portrait later.


And if you want to read about more great women in the history of psychology and neuroscience, keep your eyes peeled for my History of Women in Psychology and Neuroscience, which is coming in the Spring of 2024 from Pen and Sword books!

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