Professor Doris Tsao

Doris Tsao’s Mind—and Yours

One morning, Doris Tsao (BS ’96) woke up wondering, “Is space infinite or not?” Infinite space would be mind-boggling. But if space were finite, there would have to be something beyond it.

It was 1986 and she was a sixth grader in College Park, Maryland. She didn’t like science. From what she learned in school, she never would have guessed that scientists explore huge questions like the one that had popped into her head.

Instead, it was Tsao’s father who nurtured her curiosity. He is a machine-vision researcher, and by looking to his example and the biographies of great scientists she read, Tsao began to see science as a path to an interesting, important life. It was her father who told her about Caltech.

In the summer before her first term at Caltech, Tsao read Feynman’s lectures on physics. It was then that she glimpsed in science, as she says here, “another world where one could see beneath the surface of things, ask why, why, why, why?”

When she came to Caltech, some of the other students seemed far beyond her. And some of her experiments didn’t work. But her father’s complete belief in her had helped her build strong self-esteem, so she was undaunted in her pursuit of big questions.

A Completely New Way of Thinking

As a graduate student, Tsao was inspired to focus on neuroscience, in part, by a Penrose triangle. In one version of the impossible object, Roger Penrose labeled the vertices as the physical, mental, and platonic (mathematical) worlds.

“What’s really beautiful,” Tsao says, “is how each of these worlds, in a sense, begets the other two.”

She saw that neuroscience traditionally has focused on our physical brains and our mental experiences, leaving the mathematical strategies our brains use relatively unexplored.

“Understanding the brain requires a completely new way of thinking,” Tsao says. “The synthesis between math and biology hasn’t occurred yet.”

Intent on making the most important contribution she could, Tsao chose to pioneer that new way of thinking. As a neuroscientist, she would be able to probe the deep interface of all three worlds.

Figuring Out the Brain

Now a Caltech professor, Tsao is developing a mathematical theory of vision. It will distill how our brains convert the flood of pixels that pours through our optic nerves into a useful representation of the actual objects and space around us. Last year, her group showed that we use a simple mathematical system to recognize each other’s faces.

Tsao’s work combines computational modeling, biological investigation, and behavioral experiments with animals. “We study non-human primates because they see just like us,” Tsao says, “and we study rodents because of all the amazing tools available to probe the rodent brain.”

“There’s no perfect system and a big part of the challenge of neuroscience is finding the right system for the questions you’re interested in,” Tsao says. “For example, because we’re such highly visual animals, we have very strong intuitions about how vision works.  But these intuitions can be misleading when studying how other animals see.” Recently, her group tried to train mice to watch an object move against a background that moved in the opposite direction, but the mice couldn’t see it. “It’s not clear that they have this very basic circuit that it seems we have for picking out objects.”

Tsao’s findings have appeared in major journals for more than a decade and she is an HHMI Investigator. But to her, these accomplishments are just the first step.

Impossible Problem, Simple Solution

Tsao has a deceptively simple plan for decoding the whole brain. Last year, her strategy gained momentum when she was named director and leadership chair of the T&C Chen Center for Systems Neuroscience within the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech.

“My goal is for the center to break down walls,” she says.

“There are people studying perception, people studying cognition, people studying memory. And we rarely talk to each other. Many of us also study different organisms. You’re a fly person, a worm person.”

In Tsao’s view, if she and other neuroscientists overcome the barriers imposed by their subfields’ different techniques and terms, they can see what the common computational problems are and apply their separate strengths to answer big questions.

She envisions the united community modeling, proving, and revealing the amazing mechanisms our minds use to take in the world, think about it, and choose what we do.

The philanthropically funded leadership chair provides her, as the center’s director, with discretionary money. Already, she is using it to seed-fund collaborations that bring in scientists with broad perspectives. Soon, she plans to give graduate students their own grants, “so they can get together with their buddies in other labs and pursue their own projects.”

“The mission of the center will take many years to achieve,” Tsao says. “Perhaps the most important resource we can develop is curious young minds eager to solve the brain.”

And she has a message for those future scientists.

“You can discover something great,” she says. “You will discover something great. Don’t worry about failures or other people seeming smarter than you. That is completely irrelevant. If this is something you want to do, you absolutely will achieve it.”

Giving Priorities