Researcher of the Month
Envisioned by Dr. Jeannette M. Wing, Executive Vice President for Research, the “Researcher of the Month” series celebrates Columbia University researchers at all levels — students, faculty, and postdocs — by showcasing their scientific contributions, passion for their work, and personal stories. Explore their inspiring stories and insights below!
“By uncovering the brain's fundamental principles, we aim to provide insight into the roots of neurological disorders—and support discoveries that can ultimately help transform lives.”
At Columbia University’s Zuckerman Mind, Brain, and Behavior Institute, Dr. Vikram Gadagkar, Assistant Professor of Neuroscience, leads a research project that investigates how brains learn from experience by producing and evaluating existing and new behaviors. Using zebra finches as a model system, his lab studies the neural mechanisms of trial-and-error learning, a process that underpins how both animals and humans acquire complex motor skills like speech or music.
Dr. Gadagkar’s fascination with the brain began early in life. As a child growing up in India, he was captivated by questions about behavior—especially what happens in animals’ brains when they learn something new. This budding curiosity crystallized when he attended a talk by renowned Indian American neuroscientist V. S. Ramachandran, whose pioneering work on phantom limbs demonstrated how sensations could persist in the brain even after a limb was lost. “I was completely blown away,” Dr. Gadagkar recalls. “I decided that I was going to grow up and be a neuroscientist.”
Despite his early dream of pursuing neuroscience, Dr. Gadagkar’s academic path initially led him elsewhere. Drawn to the rigor of quantitative science, he studied physics, chemistry, and mathematics as an undergraduate, and then went on to earn a PhD in fundamental physics at Cornell University. He even worked with a professor who was exploring exotic states of matter, such as supersolids. However, he ultimately changed his mind about long-term plans. “At the end of my PhD, I realized that if I wanted to follow my childhood dream of doing neuroscience, then this was the time,” he says.
Now, as a neuroscientist, Dr. Gadagkar is deeply engaged in collaborating with his lab to uncover how the brain learns and improves. “We are interested in trying to figure out how the brain gets better with practice,” he explains. “We’re asking: How does the brain actually improve through trial and error?”
To answer this question, a central focus of Dr. Gadagkar’s work is dopamine, a neuromodulator that his lab has shown acts as a performance prediction error signal. In juvenile zebra finches learning to sing, dopamine levels increase when the bird produces a syllable that closely matches the memorized version of the father’s song, but dopamine levels decrease when the match is poor. “Dopamine provides an evaluation signal for song learning,” Dr. Gadagkar explains.
To capture this evaluation signal, Dr. Gadagkar and collaborators developed a powerful tool for studying learning by creating the first ever dopamine photometry system for birds. By introducing genetically encoded receptors that emit light in the presence of dopamine, Dr. Gadagkar and collaborators can continuously monitor birds’ neural activity during song practice—and garner detailed analysis and understanding of birds’ learning processes.
This research draws on connections with artificial intelligence (AI), particularly reinforcement learning (RL), which has become a cornerstone of modern AI. “Reinforcement learning and its variants have emerged as some of the most successful AI algorithms in recent years,” Dr. Gadagkar says. “But even in AI systems like AlphaGo, early stages of learning often rely on supervised input before RL can be developed effectively.” With this in mind, in biological systems, this raises an open question: Can reinforcement learning alone account for skill acquisition early in development?
“We showed that midbrain dopamine neurons provide a performance prediction error signal in adult zebra finches,” Dr. Gadagkar explains. “But predictions are needed before the brain can generate a reinforcement signal. So does the very young brain first need to learn the mapping between motor output and sensory feedback before it can even make a prediction?” His lab is now addressing this foundational question through longitudinal studies of juvenile learning.
Additionally, looking ahead, Dr. Gadagkar’s lab is expanding its focus to include social behavior and female zebra finches, who evaluate male song during courtship. “Most of neuroscience has focused on how the brain produces behavior,” Dr. Gadagkar says. “We know very little about how one brain evaluates the behavior of another.” By using female birds as a model of social evaluation, the lab hopes to illuminate how neural systems assess external actions—a topic relevant to social cognition.
Overall, Dr. Gadagkar is striving to answer longstanding questions about how we learn and evaluate the world around us. With the ultimate goal of improving lives, he and his team look forward to continuing their work developing a deeper understanding of the brain. “Our goal is to combine the advantages of the songbird courtship system with state-of-the-art computational, theoretical, and experimental approaches to discover how brains evaluate behaviors, both self-generated and the behaviors of others,” he says.
“Curiosity is the compass that guides us through the unknown. In research, even a null result holds the power to reshape our questions and deepen our understanding. Excellence lies not just in seeking answers—but also in embracing the journey of learning, one rigorous step at a time.”
A psychology major at Columbia University’s School of General Studies, Ava Kamdem exemplifies courage and determination. As a survivor of human trafficking, Ava has transformed her firsthand experiences into a profound drive to understand and address systemic injustices through research and advocacy. As a Social Impact Fellow and Global Thought Scholar with Columbia World Projects, Ava’s work combines academic rigor with a personal mission to create meaningful societal change.
Ava’s journey to Columbia began after she earned her GED and attended community college in Texas. “I came to Columbia in September 2022, driven by a profound fascination with the mind—an interest shaped by my lived experience of overcoming manipulation, coercion, and systemic injustice,” she explains.
Ava has channeled her passion for social psychology into impactful research, working under the mentorship of Professor Geraldine Downey on Project Restore Bed-Stuy, a gang-violence intervention program. As part of this, Ava’s research examines the impact of Project Restore Bed-Stuy’s intervention program on social networks and social capital—critical factors she believes can transform lives for former gang members.
Drawing from her own journey, Ava deeply understands the life-changing role that social capital, built through strong networks, played in her ability to rebuild her life. She faced systemic barriers common for survivors of human trafficking, such as difficulties in securing employment, housing, banking services, and even obtaining a phone plan. Overcoming these obstacles enabled her to return to school and ultimately find her place at Columbia. Reflecting on her experience, Ava shares, “It was people with privilege and vast social networks who generously advocated for me and helped me rebuild my life.”
Based on her experience, and motivated to help others in similar situations, Ava’s research for Project Restore Bed-Stuy is driven by a key question: “Does this intervention program increase participants’ social networks and social capital?” Before the intervention, participants averaged just 38 connections, primarily within their close inner circles, such as family. However, following the intervention, their networks expanded to an average of 411 connections. This growth encompasses not only personal relationships, but also broader support systems and professional connections. By fostering these multi-tiered networks, Project Restore Bed-Stuy provides participants with a vital foundation for personal growth, professional advancement, and reintegration into society.
Now, hoping to help even more people, Ava is applying to PhD programs and aiming to advance research on stigmatization and employment discrimination faced by women survivors of human trafficking. Her goal is to develop interventions that empower these women to secure meaningful employment and access economic opportunities. By focusing on the intersection of social capital and organizational behavior, Ava seeks to merge these fields to effect tangible change.
Ava’s scholarly work is complemented by her advocacy for stigmatized populations, including survivors of trafficking and formerly incarcerated individuals. She envisions a world where these individuals are seen as assets, not liabilities. “They bring invaluable soft skills and novel thinking to business and academia,” she emphasizes. Ava hopes her research will contribute to shifting societal narratives and reducing discrimination against these groups.
Through everything, Ava has a remarkable spirit of pushing forward with courage and gratitude—turning every challenge into an opportunity for growth and transformation. “I knew I had a dream and a vision, and I understood that my survival was something thousands, even millions, of women don’t get to experience. That realization gave me both the privilege and the responsibility to move forward and push past perceived barriers. As I grew into who I am today, I have never moved forward as if I didn’t belong. I believe that everyone with my lived experience, or similar experiences, deserves an equal seat at the table.”
Outside her academic pursuits and applying to PhD programs, Ava finds joy and balance with her family, especially her young son. She also prioritizes physical and mental well-being, seeing therapy and self-care as essential components of her success.
Ava’s story is a testament to the power of resilience and the transformative potential of research. Through her work, Ava not only advances our understanding of critical societal issues—but also inspires others to break barriers and redefine what is possible.
“Despite immense challenges, including the loss of my mentor and navigating uncertainty, I have remained deeply committed to my research. I investigate how and why breast cancer can relapse years or even decades later, and I explore new ways to prevent it. I continue to push forward with my research — driven by its potential to profoundly impact patients and their families.”
As a cancer researcher at the Ryeom Lab in the Department of Surgery, Seongyeon Bae is advancing critical knowledge in the fight against breast cancer metastasis. Originally from South Korea, Seongyeon’s work focuses on understanding cancer dormancy, a phenomenon that enables relapse decades after initial remission. Her pursuit is not only a scientific challenge, but also a deeply personal mission inspired by her mother’s experience with breast cancer. “The unpredictable nature of metastatic relapse is a significant problem,” Seongyeon explains. “I’m committed to uncovering the mechanisms behind it to identify new therapeutic approaches.”
Seongyeon’s research blends traditional experimental techniques with emerging computational methods, including bioinformatics. Her studies use mouse models and genomic analyses to explore why and how cancer cells become dormant and what triggers their reactivation. “I’m fascinated by the why,” she says. “Understanding the mechanisms behind these phenomena — and finding ways to regulate them — is both challenging and exhilarating,” says Seongyeon, whose dream from a young age was to become a scientist.
Seongyeon’s path to conduct research has been marked by extraordinary resilience. She began her postdoctoral training under the renowned Dr. Filippo Giancotti at MD Anderson Cancer Center, where she honed her expertise in metastatic dormancy models. When Dr. Giancotti transitioned to Columbia, Seongyeon followed him to continue her postdoctoral work under his mentorship.
However, Seongyeon’s journey took a heartbreaking turn after the move to Columbia, when Dr. Giancotti was diagnosed with terminal cancer. “Everything fell apart,” Seongyeon recalls, as Dr. Giancotti’s diagnosis not only brought the lab’s work to a standstill, but also meant she had to cope with the profound loss of a mentor who had been a guiding figure in her career.
As a junior postdoc at the time, Seongyeon faced the daunting task of navigating her research without guidance, while also grappling with personal grief and professional uncertainty. “During that time, I questioned whether I should abandon my project altogether,” Seongyeon recalls. She felt she had nowhere to go, and faced the possibility of her research coming to an abrupt end.
Despite these challenges, Seongyeon ultimately prevailed with determination and garnered new support to continue her research. “I really invested a lot in this project and I wanted to see it through,” Seongyeon said.
Dr. Sandra Ryeom became Seongyeon’s mentor, throwing her a rope and believing in her potential. In addition to offering a job, Dr. Ryeom enabled the opportunity for Seongyeon to continue her project. With the support of Dr. Ryeom and Dr. Ron DePinho, a collaborator at MD Anderson Cancer Center who also provided invaluable guidance, Seongyeon salvaged her research and continued her work at Columbia. “I was in the dark – but Dr. Ryeom’s mentorship at a time when I needed it the most, and her belief in my potential, gave me the strength to keep going,” Seongyeon shares.
Beyond her own research endeavors, Seongyeon is equally passionate about mentoring the next generation of researchers. She dreams of becoming a Principal Investigator and solving the most difficult questions of breast cancer research. Having experienced firsthand the profound impact of empathetic guidance during her most challenging moments, she aspires to be a source of support and inspiration for others. “If I can succeed after overcoming these obstacles, I want to help others navigate their own challenges,” she shares.
Seongyeon’s story is a powerful reminder of the resilience required to thrive in the face of adversity. Her journey, fueled by personal motivation and supported by compassionate mentorship, illustrates the transformative impact of perseverance in science and research. As she continues to push the boundaries of cancer research, Seongyeon exemplifies the profound influence one researcher can have — not only in the laboratory, but also in the lives of those they inspire.
“I feel lucky to work on answering questions that are not only deeply interesting and fun to explore, but also profoundly impactful — shaping how we solve problems across so many areas of computation, from advancing machine learning systems like ChatGPT, to strengthening cryptography and making algorithms faster and more efficient.”
As a theoretical computer scientist, Josh Alman is dedicated to exploring the possibilities and limitations of computation through the lens of algebraic algorithms. Building on a lifelong love of math and puzzles, Josh has emerged as a leader in advancing the efficiency of computational processes. His research focuses on using mathematical tools to create faster algorithms.
In areas such as matrix multiplication — a cornerstone of modern computational systems — Josh’s contributions are particularly impactful. One compelling example of his work’s significance is its application to large language models like ChatGPT. When users ask ChatGPT a question, the system converts the input into an algebraic object called a vector. The model then performs extensive algebraic operations on that vector, such as matrix multiplication, to produce a coherent response. In other words, “When you ask it a question, in the background it is actually doing lots and lots of algebra — and then spitting out an answer at the end,” Josh explains. His research aims to optimize these algebraic operations by making them faster, using less energy and hardware, and ultimately enhancing the performance of AI technologies.
Josh describes his work as a unique intersection of intellectual curiosity and real-world impact. “I feel like I get to work all the time on these really interesting, fun puzzles — but simultaneously, I am hopefully making progress on answering important questions that will really help people in a lot of different domains of computation,” Josh shares. He feels fortunate to work in a field where answering questions he finds fascinating can also have significant, positive impacts on the broader world of computation. A lifelong learner, Josh is also deeply curious about neighboring areas of computer science, and he enjoys developing new connections between them to apply novel insights and techniques to his work.
In addition to his professional achievements, Josh also enjoys spending time with his family, especially exploring New York City together. From visiting parks and museums, to discovering kid-friendly restaurants, he embraces the city’s vibrant opportunities for family fun. In his personal time, he indulges in his love of video games. His enthusiasm for League of Legends even inspired him to write a research paper during his PhD on the computer science underlying the game.
Josh also has a long-standing passion for puzzles. He says, “I really enjoy solving puzzles, and participating in and making something called ‘puzzle hunts,’ which are collections of puzzles where you get together with your team and race other teams to solve all the puzzles as quickly as possible.” For over a decade, with friends he has been creating “puzzle hunts,” which he releases online for others to solve.
Josh is quick to credit much of his success to the collaborative nature of his field. “Mathematics and theoretical computer science are very collaborative areas, and I work together with so many great students, postdocs, and faculty at Columbia and around the world,” he says. “A lot of my research successes really should be attributed to them.” This sense of gratitude reflects his belief in the power of teamwork and mentorship, further cementing his role as a pioneer in theoretical computer science and an inspiration to the next generation of researchers.