The Center
For
Cognitive Science
Cognitive Science Colloquium
Wednesday, 2 March, 2:00 P.M.
280 Park Hall
Richard L. Lewis
Department of Psychology & Department of Linguistics
University of Michigan
Bounded Optimality in Language, Thought, and Action:
Adaptation under Cognitive Constraint
and Its Implications for Understanding Individual Differences
In this presentation, we explore a theoretical framework that construes cognitive and linguistic processing as
boundedly optimal control problems—as rational processes constrained by both the structure of the external
environment and the structure and limitations of the cognitive architecture. Underlying the approach are
computational methods for evaluating large spaces of possible behavioral strategies in terms of their expected utility
given these constraints, rather than their fit to observed data. We demonstrate the generality of the approach through
its application to elementary dual-tasking, "fast-and-frugal" decision making, verbal short-term memory, and eyemovement control in reading. A key theoretical payoff is an understanding of individual differences in performance
as the empirical signatures of strategies that are adaptations to individually varying processing constraints. We
discuss how the framework builds on and complements related approaches, including rational analysis, bounded
rationality, Bayesian modeling, architectures, reinforcement learning, and signal-detection theory. The key feature of
bounded optimality is the theoretical role assigned to processing constraints: They are used to help define the
optimization problem, rather than used to explain departures from optimality.
RECOMMENDED READING:
Howes, Andrew; Lewis, Richard L.; & Vera, Alonso (2009), "Rational Adaptation under Task and Procesing
Constraints: Implications for Testing Theories of Cognition and Action", Psychological Review 116(4): 717–751.