A Neuroeconomics Approach to Inferring Utility Functions in Sensorimotor Control

TLDR

Utility functions and indifference curves, concepts from economics, have been used to model decision making and may also describe desirability in sensorimotor control. The study investigates indifference curves for forces varying in magnitude and duration. Using a two‑alternative forced‑choice paradigm, subjects chose between different magnitude‑duration profiles, allowing the authors to infer the indifference curves and underlying utility function. The inferred utility function depends nonlinearly on force magnitude and duration and is remarkably conserved across subjects, indicating that economic utility concepts apply to sensorimotor control.

Abstract

Making choices is a fundamental aspect of human life. For over a century experimental economists have characterized the decisions people make based on the concept of a utility function. This function increases with increasing desirability of the outcome, and people are assumed to make decisions so as to maximize utility. When utility depends on several variables, indifference curves arise that represent outcomes with identical utility that are therefore equally desirable. Whereas in economics utility is studied in terms of goods and services, the sensorimotor system may also have utility functions defining the desirability of various outcomes. Here, we investigate the indifference curves when subjects experience forces of varying magnitude and duration. Using a two-alternative forced-choice paradigm, in which subjects chose between different magnitude-duration profiles, we inferred the indifference curves and the utility function. Such a utility function defines, for example, whether subjects prefer to lift a 4-kg weight for 30 s or a 1-kg weight for a minute. The measured utility function depends nonlinearly on the force magnitude and duration and was remarkably conserved across subjects. This suggests that the utility function, a central concept in economics, may be applicable to the study of sensorimotor control.