Javier Masís named 2020 Presidential Postdoctoral Research Fellow

Javier Masís has been named a 2020 Presidential Postdoctoral Research Fellow, one of sixteen scholars from an array of disciplines across the university to receive the honor. Masís will join the Princeton Neuroscience Institute in the Fall of 2020. 

Masís recently completed his PhD in neuroscience at Harvard University, where he studied the impact of learning on decision making. He sought to understand how rats adaptively balance the competing interests of making decisions quickly and making them correctly, known as the “speed-accuracy tradeoff”, as they learned a task. Masís found that, when beginning to learn a decision-making task, rats arrived at decisions too slowly, and consequently forfeited potential rewards. But as they learned, their speed-accuracy tradeoff improved, ultimately leading to near-optimal behavior. To understand why rats sacrifice rewards early in learning, Masís turned to computational models. In the models, he found the same counterintuitive behavior seen in rats, a slow initial response. The models revealed the logic of this behavior: a learning strategy that stressed slower responses early in learning dramatically increased learning speed, yielding a larger total reward in the long run. Collectively, his results suggest that prioritizing learning over performance, early on, can yield considerable advantages.

Masís’ connections to Princeton run deep—he completed his undergraduate studies in the Department of Molecular Biology (BA ‘13) and his brother, Rolando Masís, is a PhD student in Neuroscience—leading him inexorably back. At the Princeton Neuroscience Institute, Masís will transition away from experimental work towards theoretical work, with a focus on studying human behavior. This transition seems natural to Masís: “Princeton is the perfect place for computational and theoretical neuroscience so I am super excited about the opportunity.” He plans to study learning as a cognitive control problem, one that can be described in terms of bounded optimality, a theory that describes how utility maximizing subjects make choices in the face of external constraints. He will be advised by Jonathan Cohen, Professor of Psychology and Neuroscience and the Co-Director of the Princeton Neuroscience Institute.

The Fellows program is intended to recognize and support scholars who can enrich the diversity of experiences and perspectives within the University’s community, including persons from groups that have been historically and are presently underrepresented in the academic profession. Masís grew up in Costa Rica amongst a tight-knit extended family and moved to the United States at the age of 12. “I cherish the fortune I have in being able to claim two countries as home”, says Masís. The Princeton Neuroscience Institute is excited that Masís will soon return to, what might be, his academic home. 



by Brian DePasquale

Thursday, June 4, 2020 - 2:15pm