Ila Fiat studied how the brain performs complex computations


While postdoc about 15 years ago, Ila Fiete began looking for faculty jobs in computational neuroscience – a field that uses mathematical tools to investigate brain function. However, there were no advertised positions in theoretical or computational neuroscience in the United States at that time.

“It wasn’t really a field,” she recalls. “He’s completely changed, and [now] There are 15 to 20 openings per year. “She ended up finding a position at the Center for Learning and Memory at the University of Texas at Austin, which was open to neurobiologists with a computational background with a small handful of universities, including MIT.

Computation is the cornerstone of Fiat’s research at MIT’s McGovern Institute for Brain Research, where he is a faculty member since 2018. Using computational and mathematical techniques, she studies how the brain teaches information in a symbolic way that enables cognitive functions such as learning, memory. And reasoning about our environment.

A major research area in Fiat’s laboratory is how the brain is able to continuously calculate the position of the body in space and make constant adjustments to that estimate as we move forward.

“When we pass through the world, we can close our eyes and still have a very good estimate of where we are.” “This includes being able to update our estimate based on our sense of self-motion. There are many computations in the brain that involve moving abstractly or mentally rather than in physical space and integrating some variety or velocity signals of another. Circuits for similar views and even spatial navigation can be involved in navigating through these mental locations. “

There is no better fit

Fiete spent his childhood between Mumbai, India and the United States, where his mathematician father held a series of visiting or permanent appointments at the Institute for Advanced Study at Princeton, NJ, the University of California at Berkeley, and the University of Michigan. Ann Arbor.

In India, Fiat’s father did research at the Tata Institute of Fundamental Research, and he spent time with many other children of academics. She was always interested in biology, but also enjoyed mathematics, following in her father’s footsteps.

“My father was not a hands-on parent, wanted to teach me a lot of math, or even asked me how my math was going in school, but the effect was definitely there. Think mathematically There is a certain beauty to which I have absorbed indirectly, “she says.” My parents did not push me into academics, but I couldn’t help but be influenced by the environment. “

She spent her last two years in high school in Ann Arbor and then went to Michigan University, where she studied math and physics. While living there, he worked on graduate research projects, including two summer stunts at Indiana University and the University of Virginia, which gave his first experience in physics research. Those projects covered many topics, including proton radiation therapy, magnetic properties of single crystal materials, and low-temperature physics.

“Those three experiences really convinced me that I wanted to get into academics,” Fiat says. “It definitely seemed like the path I knew best, and I think it suits my nature as well. Even now, with more performance in other areas, I can’t think of a better fit. “

Although she was still interested in biology, she took only one course in the subject in college, holding back because she did not know how to marry biological science from a quantitative point of view. He began his undergraduate studies at Harvard University to study low temperature physics, but while living there, he decided to explore quantitative classes in biology. One of them was a systems biology course taught by the then MIT professor Sebastian Seng, which changed his career trajectory.

“It was really inspiring,” she recalls. “It was really exciting to think mathematically about interacting systems in biology. This was actually my first introduction to systems biology, and it instantly hooked me. “

He completed most of his PhD research at Seung’s Lab at MIT, where he studied how the brain uses incoming signals of velocity of movement of the head to control the condition. For example, if we want to gaze at a particular location while shaking our head, the brain must calculate and adjust the amount of tension required in the muscles around the eyes, to compensate for head movements. .

“Strange” cells

After doing her PhD, Fiat and her husband, a theoretical physicist, went to the Keavley Institute for Theoretical Physics at the University of California at Santa Barbara, where they each awarded fellowships to independent research. While living there, Fiat started working on a research topic, which she still studies today – the grid cell. These cells are located in the cortex of the entrance of the brain, enabling us to navigate our surroundings by helping the brain create a neural representation of space.

Midway through his position there, he learned of a new discovery, that when a rat wanders into an open room, a grid cell in his brain rotates the geometrically triangles at several different places in a regular pattern. Is arranged in Together, a population of grid cells forms a mesh of triangles representing the entire room. These cells have also been found in the brains of various other mammals, including humans.

“It’s amazing. It’s a very crystalline reaction,” Fiat says. “When I read about that, I fell out of my chair. At the time I knew it was something bizarre that was about the development, function and brain circuitry. Will generate so many questions about which computational study can be done. “

One question Fiat and others have investigated is why the brain needs grid cells, because it also has so-called location cells that fire at a specific location in each environment. One possible explanation, which Fiat has discovered, is that grid cells of different scales, acting together, can represent a vast number of possible locations in space and multiple dimensions of space.

“If you have a few cells that can generate parsimoniously very large coding space, you can’t use most of that coding space,” she says. “You can waste most of it, which means you can isolate things very well, in which case it is not susceptible to noise.”

Since returning to MIT, he has pursued a research topic related to what he discovered in his PhD thesis – the brain maintains neural representations where the head is located in space. In a paper published last year, he revealed that the brain generates a dimensional ring of neural activity that acts as a compass, allowing the brain to calculate the current direction of the head relative to the outside world.

Her lab also studies cognitive flexibility – the brain’s ability to perform a variety of cognitive functions.

“How is it that we can reproduce the same circuits and use them flexibly to solve many different problems, and what are the neural codes that make up for such reuse Are you responsible? ” She says. “We are also investigating theories that allow the brain to hook multiple circuits at once to solve new problems without too much reconciliation.”

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