The nematode worm C. elegans chooses between bacterial foods as if maximizing economic utility
- University of Oregon, United States
- New York University, United States
- Pomona College, United States
- Massachusetts Institute of Technology, United States
- University of California, San Diego, United States
Abstract
In value-based decision making, options are selected according to subjective values assigned by the individual to available goods and actions. Despite the importance of this faculty of the mind, the neural mechanisms of value assignments, and how choices are directed by them, remain obscure. To investigate this problem, we used a classic measure of utility maximization, the Generalized Axiom of Revealed Preference, to quantify internal consistency of food preferences in Caenorhabditis elegans, a nematode worm with a nervous system of only 302 neurons. Using a novel combination of microfluidics and electrophysiology, we found that C. elegans food choices fulfill the necessary and sufficient conditions for utility maximization, indicating that nematodes behave as if they maintain, and attempt to maximize, an underlying representation of subjective value. Food choices are well-fit by a utility function widely used to model human consumers. Moreover, as in many other animals, subjective values in C. elegans are learned, a process we find requires intact dopamine signaling. Differential responses of identified chemosensory neurons to foods with distinct growth potentials are amplified by prior consumption of these foods, suggesting that these neurons may be part of a value-assignment system. The demonstration of utility maximization in an organism with a very small nervous system sets a new lower bound on the computational requirements for utility maximization and offers the prospect of an essentially complete explanation of value-based decision making at single neuron resolution in this organism.
Data availability
Data of Figures 2, 4, 5-9 are available as Source Data files associated with this publication.
Article and author information
Author details
Elizabeth E Glater
Funding
National Institute of Mental Health (MH051383)
- Shawn R Lockery
National Institute of General Medical Sciences (GM129576)
- Shawn R Lockery
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Katzen et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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The nematode worm C. elegans chooses between bacterial foods as if maximizing economic utility
eLife 12:e69779.
https://doi.org/10.7554/eLife.69779
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