In 1972, Leon Cooper won a Nobel Prize in Physics.

In 1973, he founded the Institute for Brain and Neural Systems. 

It was a stunning pivot: from electrons to neurons, from physical science to life science. Cooper, who died this fall at the age of 94, loved nothing better than an intellectual challenge. Understanding the brain – a subject as powerful and mysterious as the sea or stars – was a worthy provocation. For four decades at Brown, Cooper pursued his curiosity about the brain and mind and, in the process, served as a catalyst for brain science on campus: recruiting talent, creating culture, and inspiring thousands of undergraduates by seeding the university’s legendary Neuro 001 course.

“Leon Cooper played a huge role in brain science at Brown,” said John Donoghue, founding chair of the Department of Neuroscience and former director of the Brown Institute for Brain Science. “Along with a handful of others on campus, Leon saw the future of neuroscience and pressed for it. He was ahead of his time – and brought us with him.”

Cooper died October 23, 2024, in Providence, his home since 1958, when he arrived to begin a 56-year tenure at Brown as a professor of physics. Cooper is renowned for deciphering the puzzle of superconductivity, the capacity of certain materials to conduct electrical currents with no resistance. It’s a phenomenon that makes faster computer chips and more efficient power grids, and powers MRI machines and particle accelerators.

In time, Cooper gained fame again – for a brain science breakthrough. 

Along with his Ph.D. students Elie Bienenstock and Paul Munro, Cooper developed a theoretical model for how neurons adapt their connections based on their recent firing patterns. The model, called the BCM theory in a nod to its authors, is a singular contribution. BCM theory provided a theoretical foundation for the phenomenon of synaptic plasticity – neurons’ ability to change over time, a process that makes possible learning and memory, as well as changes to the brain during development and disease. 

Cooper also made significant contributions to the creation of neural networks, which are mathematical instructions inspired by the brain’s structure and function. Neural networks run computer code, power navigation systems and help machines learn. They’re a core technology in artificial intelligence.

Cooper was keen to understand how the brain works – and knew no single field of science could explain it. Back in the early 1970s, neuroscience was in its infancy, existing only as a formal program at MIT and the University of California, Irvine, where the department was called “psychobiology.” Flush with the power that comes with a Nobel Prize, Cooper set out to create a similar program at Brown. For that, he would need to attract new talent. 

In 1973, Cooper travelled to Rockefeller University in New York City to meet a promising young scientist studying the cerebellums of pigeons. His name: James Anderson.

“Leon was very good at extracting support, and I was one of the things he extracted,” Anderson laughed as he recalled his recruitment. “He came to my lab and saw some of my apparatus and he was genuinely horrified. He said: ‘This is not how you want to do science.’ And I agreed.”

At Brown, Anderson would become an international authority in neural networks, serve as a two-time chair of the Department of Cognitive and Psychological Sciences, and act as a beloved colleague and mentor for more than four decades.  Anderson also served as the first faculty advisor for the neuroscience concentration, a new field of undergraduate study that spun out of the success of Neuro 001, Brown’s first brain science class. 

The course was launched in the late 1970s with Cooper’s support. Anderson recalls that the course was taught by a team: Cooper, the physicist; Anderson, trained in both physics and physiology; Jim McIlwain, a physician and biologist; Russ Church, a psychologist; and Ford Ebner, a psychologist and biologist.

“It was fun,” Anderson said. “Brown had one of the nation’s best psychology programs in the 1950s and then we had all these people interested in the brain and the mind. We didn’t know how to do interdisciplinary science back then, but we knew how to teach, and we knew we needed different perspectives to explain the brain.”

Along with recruiting faculty – including engineer Jerry Daniels – Cooper was a magnet for promising PhD students and postdocs like Michael Paradiso, now a professor in the Department of Neuroscience and the long-time instructor for Neuro 001. Cooper brought faculty together, along with students and visiting scientists of all stripes, on the seventh floor of Barus & Holley, the home of the Institute for Brain and Neural Systems. It was a sort of souped-up research lab and science salon, a place where Cooper could convene experts who could advance the theory and experiments behind his work. 

Colleagues said that by gathering a variety of researchers – from applied math and physics, biology and psychology – Cooper created the interdisciplinary ethos that’s not only the hallmark of the Robert J. and Nancy D. Carney Institute for Brain Science, but the hallmark of research at Brown. 

“No one could bring people together like Leon could,” Donoghue said. “He was an intellectual powerhouse, and those meetings had a big impact on me. I was there with all these faculty, and a Nobel Laureate, but I felt like a peer. I learned so much. So did Leon. He really wanted to understand how the cerebral cortex works. He gave me an appreciation for an interdisciplinary approach. That was Leon’s contribution. He did that before anyone else at Brown.”

Mark Bear entered Cooper’s orbit in 1979. Bear came to Brown to earn a doctoral degree in neurobiology and studied the visual cortex with Ebner. Bear was fresh out of Duke University and awed to meet Cooper, “the first Nobel Laureate whose hand I ever shook.”

“Leon was curious about everything and was a clear and creative thinker,” Bear said. “He was generous. He was arrogant – and he earned it. He was good at piecing things together that most people wouldn’t piece together. Or couldn’t. That’s the mark of a great scientist. Leon was also very good at relationships. He was always drawing people in, asking them questions, bringing them into the conversation. He’d break out a bottle of scotch in his office, and I’d school him in biology, and he’s school me in theory. There would be these wonderful exchanges of knowledge and excitement.”

For years, Bear met with Cooper every Tuesday to talk about the BCM theory and the experiments that could test it. Bear, Ebner and Cooper got a government grant and worked together to study neural networks. Cooper told Bear that if, after his postdoctoral fellowship in Germany, he wanted to come back to Brown, he would lobby for him. 

And he did. Bear joined the Brown faculty in 1986, with a position in what was then called the Center for Neural Science which, six years later, became the Department of Neuroscience. Bear took on responsibility for leading Neuro 001 and worked closely on the course with Ebner, McIlwain and neuroscientist Mitch Glickstein. Cooper always delivered a lecture. Bear said Cooper and other brain science leaders believed that the subject should be accessible to undergraduates – and they responded.

“The course was a hit, right out of the gate,” Bear said. “Enrollment swelled to 250, 300 students. The course was fun because it was like a string of great performances. There was no department sponsor, just this incredible group of like-minded people getting up there talking about the brain. It was so Brown.”

 Carlos Aizenman, a professor of neuroscience, attended Brown as an undergraduate. He vividly remembers Cooper’s Neuro 001 lecture. Cooper told students that the year before in the course, he argued a specific point and that this year he would refute that point. Which he did, for 90 minutes, without notes. Aizenman went on to work in Mark Bear’s lab, and, one day, went with Bear to meet Cooper. The scotch came out, and Aizenman was surprised that he could follow what Cooper was saying about their study results – and that Cooper asked his opinion on the findings.

“He had a way of making people feel welcome and included,” Aizenman said. “I’m sitting there, an undergraduate, with these faculty members, and talking about our results and I remember thinking: ‘Hey, I could be part of this science thing.’”

Ford Foundation Professor of Physics Gang Xiao, whose office was next to Cooper’s book-strewn suite for more than 20 years, was similarly inspired. Often, the two would talk about science, art or their work. Cooper would encourage Xiao to study something outside of physics and engineering. Now he is. Xiao collaborates with Carney neuroscientist Jerome Sanes to develop a non-invasive, magnetic brain sensor, a project partially funded by Carney’s Zimmerman Innovation Awards in Brain Science.

“Leon was always interested in applications, so he would be very proud of this project,” Xiao said, “The brain is very complicated, and in physics, we like complicated problems.”

Luk Chong Yeung was similarly encouraged by Cooper.

Yeung grew up in Brazil and met the famous physicist when he visited Nestor Caticha, her advisor and an expert in neural networks. Cooper encouraged her to apply to Brown to earn her PhD in physics. She did, and Cooper advised her. After defending her dissertation in 2004, Yeung stayed another two years to conduct postdoctoral research in neuroscience.

“Because of Leon I went to Brown and because I went to Brown, I changed my destiny,” Yeung said. “Not only did I grow as a thinker, I made life-long friends and valuable memories. I even married a fellow graduate student. To say that Leon changed my life is an understatement.”

Looking back, 20 years after graduation, Yeung’s appreciation for Cooper has deepened. 

“It is a testament to his deep knowledge in physics, which is mystifying to many, that Leon was able to make things seem easy,” she said. “However, it is a demonstration of his wisdom and kindness that, despite his stature, he made you feel smart. Leon didn't need to take seriously a little Chinese Brazilian girl who didn't know what she was doing, but he did. That to me was what elevated him above others.

“Leon had complete mastery over superconductivity but ventured into a different domain. Doing something like that demands a rare combination of confidence and humility. Many struggle to make a mark in even one discipline, but Leon left a lasting legacy in two profoundly challenging fields.”