Biomagnetism is the study of the magnetic fields produecd by the body, specifically by electrical activity occurring in biological tissue, such as in the brain, heart and muscles. Launched by researcher David Cohen in conjunction with a technology he introduced—the technology that would become magnetoencephalography (MEG)—the field of biomagnetism has yielded countless insights in both science and medicine.
Not least of the insights: by enabling researchers to map activity in the brain, MEG technology has helped shed light on the nature of epilepsy and other neurological disorders and advanced applications including presurgical planning in epilepsy.
David’s impact on the study of biomagnetism cannot be overstated. Even beyond launching the field, he has devoted himself fully to improving the technology, exploring further applications and supporting the increasingly active biomagnetism community, Indeed, one could say, without hyperbole, that he has lived his entire life in the pull of magnetism.
From his childhood in 1920s and ’30s Winnipeg, where his uncle was an electrician and tinkerer who introduced him to the principles of magnetism via crystal set radios, to his graduate studies in experimental nuclear physics at the University of California, Berkeley, in the years after World War II; from a job as an accelerator physicist at Argonne National Laboratory to a series of academic positions; the major throughline in his life has been a fascination with the principles of magnetism and the many ways in which magnetism can be wielded.
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David introduced the technology enabling the study of biomagnetism in the late 1960s, through work he conducted first at the University of Illinois, Chicago, and then at the Massachusetts Institute of Technology (MIT). In fact, the first unambiguous demonstration of the technology, using the superconducting quantum interference device (SQUID) developed by his collaborator James Zimmerman, came at the tail end of the decade, on New Year’s Eve 1969.
Having launched a new field of study based on the technology—the journal Science would later describe the New Year’s Eve experiment toward a particular subject. As with any scientific advance, the invention of MEG was not simply the result of an arbitrary decision on David’s part to introduce a new biomedical device. Rather, it was the summation of intrinsic interests encouraged and shaped by family and friends, other lived experiences, and even historical circumstances.
In a series of conversations over the past several years, David shared much of his story and how events in the first four decades of his life led him to explore the very weak signals emanating from the human body—and ultimately become “the father of MEG.” In this work, we follow him on his journey, stopping to explore key moments in which he was faced with tough decisions, decisions that might have led him down very different paths had he responded other than how he did at the time. The story of any invention or innovation is, of course, the story of such moments.
(For reprints, email gboas@mgh.harvard.edu)
Image in the header courtesy of Matti Hämäläinen.
