Adaptive Computational
Cognition Laboratory
Department of Cognitive Science
Rensselaer Polytechnic Institute
Troy, NY
Department of Cognitive Science
Rensselaer Polytechnic Institute
Troy, NY
How is the brain able to accomplish complex goals, with limited computational resources, in an uncertain world?
We answer this question with mathematical theory, computational models, and experiments on human perception, memory, learning, and action.
A central principle of our research is that an optimal cognitive system is one that maximizes the utility of action, subject to constraints on the ability to store and process information. This principle lets us ask what the best possible limited system would do. We work out the answer using tools from machine learning, Bayesian statistics, and information theory, and then test those predictions against human behavior.
Computational models play a central role in all of our work. In everyday life, the complexity of the problems the brain solves is hidden from awareness. It often becomes apparent only when we try to reproduce the breadth and robustness of human behavior in a model. Building a model also forces a theory to be explicit, so that its assumptions are clear and its predictions precise. Furthermore, in many cases human performance exceeds that of existing algorithms, such as learning from sparse data and generalizing to novel situations. By studying human behavior and building computational models of cognition, we can also advance artificial intelligence and machine learning.
Above: Human perception has limited capacity, so it cannot represent the world exactly. The top plot shows this trade-off: the more information the brain can process (measured in bits), the smaller its errors can be. The curve, from rate–distortion theory, marks the best any system can possibly do. The lower plot shows what this means for a single stimulus, marked by the red line. The grey curve shows how common different stimulus values are, and the blue curve shows the range of percepts the best possible system produces. Drag the slider to lower the capacity: percepts become less accurate and are pulled toward typical values. See also: (Sims, 2016) • (Sims, 2018)
We are recruiting PhD students to begin in Fall 2027. We welcome applicants from cognitive science, psychology, computer science, mathematics, engineering, and related fields who want to build formal theories of the mind and test them with human experiments. If you are interested, email Chris Sims (simsc3@rpi.edu) with a CV and a few sentences about your background and research interests. Apply through Rensselaer's graduate admissions page.
Sep. 2026: New paper is out in print in Journal of Mathematical Psychology: "Performance effects of team-coordination strategies: A temporal interaction analysis" (Banerjee, Sims, & Gray, 2026)
Sep. 2026: Welcome to Shishir Shrestha, who joins the lab as a PhD student, co-supervised with Dr. Stefan Radev.
May 2026: Congratulations to Dr. Noah Phillips on completing his PhD! His dissertation, "Quantitative and qualitative approaches to understanding and facilitating high-level cognitive-perceptual-motor skill expertise using competitive eSports".
May 2026: Congratulations to Caleb Carr (MS, Computer Science) and Rock Clapps (MS, Cognitive Science) on completing their master's degrees!
2025: Our paper "Humans learn generalizable representations through efficient coding" (Fang & Sims, 2025) published in Nature Communications!
2025: Two lab papers were presented at the Annual Meeting of the Cognitive Science Society: "Validating predictive models of extreme expertise in complex cognitive-motor skills" (Phillips & Sims, 2025) and "Examining the influence of stress and anxiety on visual working memory and decision-making" (Kaper, Walf, & Sims, 2025).
Human perception cannot capture every detail of the world, so the brain must decide what information to keep and what to discard. We use rate–distortion theory, the branch of information theory that deals with lossy compression, to predict how an optimal but capacity-limited perceptual system should behave. This approach explains how people identify stimuli and remember visual details. It also shows that Shepard's "universal law of generalization" follows from efficient coding, in biological and artificial systems alike.
See: (Sims, 2016) • (Sims, 2018)
People rarely face exactly the same situation twice, so learning is only useful if it carries over to new situations. We study how people build simplified internal representations that keep the features that predict reward and discard the rest. Adding this principle of efficient coding to reinforcement learning produces models that generalize as well as people do, where standard models fall short. This work links human learning to open problems in machine learning and artificial intelligence.
See: (Fang & Sims, 2025)
Skilled motor behavior, from reaching for a cup to competing at an elite level, depends on tightly coordinated perception and movement. We use mobile eye tracking and motion capture to measure how people move in fine-grained detail. We then develop models of motor control that account for the limits of information processing. We also study extreme expertise in complex domains such as competitive esports, and have developed new ways to test models of expert performance when there are only a few experts to study.
See: (Phillips & Sims, 2025) • (Lerch & Sims, 2016)
We study how limits on memory, attention, and other cognitive systems shape the decisions people make. Our models show that some well-known biases in human choice can arise from forming efficient representations of what we see. We also examine how a person's current state, such as stress or anxiety, changes the interplay between visual memory and decision making.
See: (Malloy & Sims, 2025) • (Kaper et al., 2025)
You can find recent publications from the laboratory via Chris Sims's Google Scholar profile.
Chris R. Sims is an Associate Professor in the Department of Cognitive Science at Rensselaer Polytechnic Institute, where he directs the Adaptive Computational Cognition (AdaCog) Laboratory. He received a B.S. in computer science from Cornell University in 2003 and a Ph.D. in cognitive science from Rensselaer in 2009. He was then a postdoctoral researcher at the University of Rochester and a faculty member at Drexel University, before returning to Rensselaer in 2017.
Sims's research seeks to identify the computational principles that underlie human intelligence, drawing on cognitive science, machine learning, and artificial intelligence. A central theme is the application of information theory to human cognition: the idea that the mind makes the best use of a limited capacity to store and process information.
In a 2018 paper in Science, Sims showed that Shepard's "universal law of generalization" follows from the principle of efficient coding. The result suggests that perception is shaped to minimize the cost of perceptual errors under constraints on information processing. Related work applies rate–distortion theory to visual working memory, explaining how the brain trades memory precision against limited capacity. This work has implications for understanding perceptual expertise in domains such as medicine.
A second line of research combines reinforcement learning with information theory. It asks how people learn behaviors and representations that maximize reward while staying as simple as possible. This work, including a 2025 paper in Nature Communications, shows that efficient coding helps explain how people generalize what they learn to new situations. Current projects in the lab extend these ideas to decision making, skilled action, and expertise.
Current:
Shishir Shrestha
Co-supervised by Dr. Stefan Radev
Alumni:
Noah Phillips
PhD 2026, "Quantitative and qualitative approaches to understanding and facilitating high-level cognitive-perceptual-motor skill expertise using competitive eSports"
Sounak Banerjee
PhD 2024, "Fluid role structure in teams: Coordination and performance in complex cooperative tasks"
Co-supervised by Dr. Wayne Gray
Tailia Malloy
PhD 2022, "Resource-Rational Cognitive Modeling: An information-theoretic Approach"
Zeming Fang
PhD 2022, "Learning Generalizable Representations Through Compression"
Rachel A. Lerch
PhD 2020, "Beyond Bounded Rationality: Towards a Theory of Computationally Rational Motor Control"
Alumni:
Caleb Carr
MS in Computer Science, 2026
Co-supervised by Dr. James Hendler
Rock Clapps
MS in Cognitive Science, 2026
Rochelle Kaper
MS in Cognitive Science, 2024
Silver Shen
MS in Cognitive Science, 2024
Email: Chris R. Sims (simsc3@rpi.edu)
Tel: 1 (518) 276-2963
Mailing address:
Chris R. Sims
Carnegie Building
Rensselaer Polytechnic Institute
110 8th St
Troy, New York 12180
Our lab is located on the third floor of the Winslow Building: