Alumna Doris Tsao (BS '96), now professor at UC Berkeley, is a recipient of the 2024 Kavli Prize in Neuroscience. She shares the prize with longtime collaborators Nancy Kanwisher of MIT and Winrich Freiwald of The Rockefeller University for their discovery of a specialized system within the brain to recognize faces.
As an undergraduate at Caltech, Tsao majored in math and biology. "The two blocks between South Wilson Avenue and South Hill Avenue became my paradise," she writes in an autobiography. "After conquering the rigors of the Caltech core curriculum together, [undergraduates] believed we could tackle any problem under the Sun. I am grateful to Caltech for giving me this sense of confidence."
Tsao attended Harvard for graduate school, where she first began the line of research that would define her career. In 1997, fellow Kavli Prize recipient Kanwisher identified an area in the human temporal lobe that appeared to be specialized for processing faces, sparking Tsao's interest. Tsao was studying the nonhuman primate brain, and together with Freiwald, the two identified similar "face patches" in the monkey brain. The subject of face patches remained a major focus of Tsao's laboratory, first at the University of Bremen in Germany and then at Caltech as a faculty member.
From 2009 to 2021, Tsao was a member of the Caltech faculty. "Warmed by rays of Southern California sunshine, I felt giddy with happiness," she recalls.
In 2017, Tsao and her team discovered the mechanism that the brain uses to represent facial identity. Even though an infinite number of different possible faces exist, they found that the brain needs only about 200 neurons to uniquely encode any face, with each neuron encoding a specific dimension of facial variability. That same year, her team showed how perturbations in these face cells alter perception. In 2020, she published a study illustrating the mathematical system that the brain uses to organize visual objects according to their principal components.
"When you see a face, it is not projected like an image onto a movie screen in your brain; the active neurons do not simply create a picture of the face which you could see with your own eyes if you looked into the brain," says Tsao's Caltech colleague David Anderson, Seymour Benzer Professor of Biology and Leadership Chair and director of the Tianqiao and Chrissy Chen Institute for Neuroscience. "Doris's groundbreaking work shows that the brain uses its own language to generate an abstract representation of a face based on the firing patterns of groups of neurons. This abstraction is presumably decoded by the rest of the brain to identify the face and decide whether and how to act on that information. Doris's later work has shown that this discovery generalizes beyond faces to explain how the brain represents other types of real-world objects, like bicycles or baseballs."
In 2015, Tsao was named a Howard Hughes Medical Institute Investigator. In 2018, she received a MacArthur Fellowship and the Perl-UNC Neuroscience Prize. In 2020, she was elected a member of the National Academy of Sciences. In 2021, she joined the faculty at UC Berkeley.