On the normative advantages of dopamine and striatal opponency for learning and choice

Abstract
Data availability
Article and author information
Metrics

Abstract

The basal ganglia (BG) contribute to reinforcement learning (RL) and decision making, but unlike artificial RL agents, it relies on complex circuitry and dynamic dopamine modulaton of opponent striatal pathways to do so. We develop the OpAL* model to assess the normative advantages of this circuitry. In OpAL*, learning induces opponent pathways to differentially emphasize the history of positive or negative outcomes for each action. Dynamic DA modulation then amplifies the pathway most tuned for the task environment. This efficient coding mechanism avoids a vexing explore-exploit tradeoff that plagues traditional RL models in sparse reward environments. OpAL* exhibits robust advantages over alternative models, particularly in environments with sparse reward and large action spaces. These advantages depend on opponent and nonlinear Hebbian plasticity mechanisms previously thought to be pathological. Finally, OpAL* captures risky choice patterns arising from DA and environmental manipulations across species, suggesting that they result from a normative biological mechanism.

Data availability

The current manuscript is a computational study, so no data have been generated for this manuscript. Simulation code is available on the authors' GitHub repositories https://github.com/amjaskir/opal-star

Article and author information

Author details

Alana Jaskir

Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, United States

For correspondence
alana_jaskir@brown.edu

Competing interests
No competing interests declared.
Michael J Frank

Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, United States

For correspondence
Michael_Frank@brown.edu

Competing interests
Michael J Frank, Senior editor, eLife.

"This ORCID iD identifies the author of this article:" 0000-0001-8451-0523

Funding

National Institute of Mental Health (P50MH119467)

Michael J Frank

National Institute of Mental Health (R01 MH084840)

Michael J Frank

National Institutes of Health (S10OD025181)

Michael J Frank

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

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.