Haim Sompolinsky

Haim Sompolinsky was born in Copenhagen, Denmark, in 1949, but grew up in Israel, where his parents emigrated when he was a young child. His father, David, was a renowned microbiologist and a World War II hero who helped hundreds of Danish Jews escape to neutral Sweden after the Nazis invaded Denmark in 1940. From his father, Sompolinsky developed an early and profound interest in science. “I was fascinated with the magical ability of physics to use mathematics to explain nature,” he recalls. “That magic mystified me—and still does, even to this day.” While completing his mandatory service in the Israeli army, Sompolinsky studied physics and mathematics at Bar-Ilan University. He received his PhD in physics in 1980 and then accepted a postdoctoral research position with Harvard University theoretical physicist Bertrand Halperin. “Halperin was a leader of condensed matter physics, so it was a natural choice to go there,” Sompolinsky says.

When the post-doc ended, Sompolinsky returned to Israel to join the faculty of the physics department at Bar-Ilan University. In 1986, he moved to the Hebrew University of Jerusalem, where he co-founded the Hebrew University Interdisciplinary Center for Neural Computation in 1992 and the Edmond and Lily Safra Center for Brain Sciences in 2009.

From the beginning of his career, Sompolinsky played a pioneering role in the field of theoretical neuroscience, creating novel mathematical models to describe how information is processed in the brain’s neural circuits. His work was fundamental in establishing an entire new field of investigation in neuroscience: neurophysics. “When I began, computational and theoretical neuroscience didn’t really exist, so it was really easy for a young physicist like me to get into the field,” Sompolinsky recalls. “Everything we did was essentially new.”

During the 1980s, Sompolinsky collaborated with two of his colleagues at Hebrew University, Daniel Amit and Hannoch Gutfreund, to produce a series of papers that lay the basis for attractor-network analysis of neural activity. (An attractor network is a network of interconnected neurons that settle into a stable, self-sustained state.) Building on the 1982 Hopfield network model, they used statistical physics to generate a rigorous quantitative theory of attractor networks, and to link this model to real biological systems. In 1995, Sompolinsky developed the ring-attractor network model and applied it to the orientation-tuning properties of neurons in the visual cortex—a theory that has since been experimentally confirmed in the navigational system of flies and mammals.

Sompolinsky has made many other seminal contributions to theoretical neuroscience. He described, for example, how neural excitation and inhibition can dynamically balance each other to produce stable patterns of activity in neural networks—findings that have profoundly influenced our understanding of brain systems. He also introduced the tempotron, a biologically plausible model of learning that decodes information embedded in the space-time patterns of the action potentials, or “spikes,” of neurons. The tempotron represented a paradigmatic shift from the older, static supervised learning model. Sompolinsky has recently begun working on extending the tempotron rule from small neural circuits to large ones—one of many projects that have him excited about the future of theoretical neuroscience.

“I’m amazed at the progress that the field has made,” he says. “Back in the 1980s and 1990s, the idea that theory could offer something useful to neuroscience was a foreign concept. At that time, biology was entirely data-driven from the bottom up. I’m immensely impressed at how fast theoretical and computational neuroscience has become a mainstream discipline in neuroscience.”

Sompolinsky currently divides his time between the Hebrew University of Jerusalem, where he is a professor emeritus of physics and neuroscience at the Racah Institute of Physics and the Edmond and Lily Safra Center for Brain Sciences, and Harvard University, where he is a professor of Molecular & Cellular Biology and Physics, in Residence. He has received many awards and accolades during his career, including membership in the European Molecular Biology Organization (EMBO) and foreign honorary membership in the American Academy of Arts and Sciences. He is married to Elisheva Sompolinsky, who is founder and managing director of an executive recruitment company in Jerusalem. They are parents of five children.