Computational Neuroscientist Opens Doors for New Ideas and Talent to Thrive
When Kanaka Rajan, PhD, an expert in neural networks, joined the Icahn School of Medicine at Mount Sinai in late 2018, it was the school’s way of investing in computational neuroscience. But since establishing her lab, she has achieved new heights not just in her area of study, but in paving roads for future diverse talents to enter what had been a rather homogenous field.
Dr. Rajan, an Assistant Professor of Neuroscience in The Friedman Brain Institute at Icahn Mount Sinai, was recently awarded the McKnight Scholar Award, a three-year honor that provides funding to early-career scientists, from the McKnight Foundation, a Minnesota-based organization that has supported work in arts and culture, neuroscience, and climate change.
“I am honored to be recognized by the McKnight Foundation this year. The announcement was such a pleasant surprise,” said Dr. Rajan. Awardees of such programs are not often pure theorists like herself, she said. But the less restricted nature of the funding will advance a new research direction her lab has taken on and will bring much needed exposure to a key problem in science: how does the brain work?
Growing the team
The Rajan lab builds recurrent neural networks—artificial networks of neural nodes or regions inspired by biological brains—toward two core goals. The first is to discover the pattern of cell activity and connectivity in the brain, especially in psychiatric disease models, using these networks. These include exploring how there might be unexpected similarities or differences across species.
One study in that vein was based on what Dr. Rajan calls “functional motifs”—brainwide neural maps that tracked motor dysfunction as a correlated passive coping mechanism, a trait associated with depression.
Larval zebrafish subjected to persistent stress were observed to shut down movement. By comparing computational models of the fish’s neural circuitry against what is known in similar studies in mice and humans, Dr. Rajan could extrapolate how multi-area brain communication and connectivity leads to behavior relevant to neuropsychiatric disease.
The second goal is studying the concept of generalized learning, in which skills learned for one task become applicable to other unrelated problems. This encompasses, among other things, how animals and people are able to multitask, and yet, unlike machines built with artificial intelligence, how people can fail to complete all or some of these tasks perfectly.
A recent breakthrough in generalized learning that Dr. Rajan is working on is getting recurrent neural networks to do “curriculum learning”—training them on designed syllabi of increasingly complex tasks.
The idea of curriculum learning is not new in psychology or cognitive neuroscience, in which animals learn through “shaping.” In a lab setting, animals can be shaped to perform a desired task through reinforcement, for example by rewarding successful completion of sequences of smaller tasks.
An illustrated look at Dr. Rajan’s work
Illustration credit: Jorge Cham
Using this method for recurrent neural networks was born partly out of recognition for how animals and children learn, and in part to address limitations of current training algorithms, Dr. Rajan said. She adds that her lab is among a handful to use curriculum learning in neuroscience, recognizing that understanding how people generalize requires understanding their full learning trajectory.
“It’s an exciting new chapter for this field and I’m hopeful the McKnight Scholar Award will help scale our efforts on this front,” Dr. Rajan said. Her team—comprising four postdoctoral researchers, some of whom are starting independent faculty positions later this year, and three graduate students—looks to add a few more members with the funding.
“This is a competitive field and city to hire scientists in,” she said. “Not only are we competing with other institutions; we’re also competing with industry, so it’s on us to make it an attractive proposition.”
But Dr. Rajan believes Mount Sinai offers something that other institutions or industry players might not: complete intellectual freedom.
“When I first arrived, I was told, ‘Welcome to the department. Let us know if you need anything,’ without any restrictions on my next steps,” Dr. Rajan recalled of her interactions with leadership in the Department of Neuroscience at Icahn Mount Sinai. “This was unlike previous institutions I had been at, where I had been gently nudged where I could or could not direct my research.”
Mapping new paths ahead
Just as Dr. Rajan felt she was given the opportunity to excel as a woman and person of color, she felt compelled to extend those opportunities to those who follow in her footsteps.
Dr. Rajan was allowed to tap her seed funding to start a pilot project in which she turned complex research papers into comic strips to get high school seniors and college students, especially those from disadvantaged communities, interested in joining the neuroscience field.
A peek at how Dr. Rajan makes complex research topics accessible to young students
Illustration credit: Jordan Collver
“There had been artificially high barriers to entry, like girls had been told they’re not good at math, or that AI and/or computational neuroscience are beyond their understanding,” Dr. Rajan said.
By turning complex ideas into jargon-free and engaging formats such as a comic strip, she hopes to help young students realize that they too can enter and flourish in such a technical field. A series of comic strips have been created and steps are underway to distribute them to schools in New York City and other cities.
“When I first started my lab, I had 116 applications to join my team. Guess how many were women?” Dr. Rajan asked. “Two. Computational neuroscience has a representation problem, and I want to fix what I can.” She continued, “I’ve taken small steps, but the ball rolled from Mount Sinai. Here, you see women really get to thrive.”