Yotaro Sueoka
The hippocampus is a brain region that builds an internal cognitive map of our surroundings to support spatial navigation. As we move through space, we face a computational challenge: We must simultaneously predict where we are going next using this map while also encoding new environmental features onto the map. How the brain achieves both at once without interference has been a mystery. A prominent theory proposes that rhythmic brain oscillations known as theta waves hold the key by enabling the hippocampus to rapidly alternate between prediction and encoding modes during different phases of each oscillation cycle. Working in the labs of Dr. James Knierim and Dr. Noah Cowan, I used electrophysiology and virtual reality in rats to provide direct evidence for this long-standing theory. These findings advance our understanding of how the brain maintains multiple parallel computations — a fundamental principle that extends beyond navigation to memory and cognition more broadly.
Questions & Answers
Why did you choose Johns Hopkins for your work?
From my first visit during interview week, I was struck by the camaraderie among students and faculty and the strong culture of interdisciplinary collaboration. This proved essential to my work; my doctoral project only became possible through the partnership between my two mentors in neuroscience and mechanical engineering.
What does receiving this award mean to you personally and professionally? Do you have any connection with the particular award you received?
I am deeply honored to receive this award and to join the distinguished group of past recipients whose work I admire. I am profoundly grateful to my advisers, who taught me both the rigor and joy of scientific discovery. This award is as much a testament to their guidance as it is to my work.
What contributed to your project’s success? (Special skills, interests, opportunities, guidance, etc.)
First and foremost, this success belongs to my mentors, Dr. Knierim and Dr. Cowan, and the collaborative environment in our labs. The main breakthrough came when I thought I had enough material for a paper and began exploring neural activity typically dismissed as “noise,” just out of curiosity. Recognizing systematic patterns in the data led to our paper’s central thesis. The combination of rigorous training and the freedom to follow unexpected leads made this discovery possible.
What thoughts do you have about Young Investigators’ Day itself, as a celebration of the roles students and fellows play in research at Johns Hopkins?
Young Investigators’ Day serves dual purposes that I deeply value. It is an inspiring window into the diverse, creative research my peers are conducting across Hopkins’ many disciplines. Equally important, it recognizes that students and fellows aren’t just learning; we are actively advancing science. The celebration affirms Hopkins’ commitment to empowering early-career researchers, which has been central to my experience here.
What has been your best/most memorable experience while at Johns Hopkins?
My first electrophysiology recording remains unforgettable. Hearing hippocampal neurons fire rhythmically through the audio monitor as the rat navigated — literally listening to the brain compute spatial information in real time — transformed my understanding of neuroscience from abstract theory to tangible reality. That moment crystallized my passion for this work.
What are your plans over the next year or so? Graduating, looking for faculty positions, etc.?
I have about a year remaining in my doctoral program, after which I will pursue a postdoctoral position to further develop my research expertise.
Tell me something interesting about yourself that makes you unique. Do you have any special hobbies, interests or life experiences?
I am an avid visitor of UNESCO World Heritage Sites. I plan my travels around these sites, which often takes me to places far off the typical tourist path. One recent trip was to Mompox, a beautiful colonial village in remote Colombia that inspired Gabriel Garcia Marquez’s magical realism!