# Uncertainty and reward histories have distinct effects on decisions after wins and losses

## TL;DR

Rats adjust their decision-making differently after wins and losses, influenced by uncertainty and past rewards, with sex differences observed in how they respond to uncertainty.

## Contribution

A reinforcement learning model is proposed to show how uncertainty and reward history modulate win and loss weighting in rats.

## Key findings

- Rats weighted wins more than losses in predictable environments with low uncertainty.
- Male rats were more influenced by uncertainty history in win-stay decisions compared to females.
- Asymmetric weighting of wins and losses helps rats adapt to changing reward and uncertainty conditions.

## Abstract

Intelligent behavior necessitates an adaptive integration of feedback. It is well-known that animals asymmetrically learn from positive and negative feedback. While asymmetrical learning is a robust behavioral effect, the latent computations behind how animals represent their environments and use this to differentially weight wins and losses is poorly understood. Here we tested whether and how uncertainty and reward history modulate the weights placed on wins and losses using a behavioral data set collected in rats. We propose a reinforcement learning model that integrates uncertainty history via an unsigned average reward prediction error and a separate subjective reward history component. We showed that in a dynamic probabilistic reversal learning task with blocks of variable reward predictability, ongoing estimation of uncertainty history and reward history both distinctly influenced rats’ sensitivity to wins and losses. In more predictable environments, and under low uncertainty levels, i.e., when rats were certain in making ‘correct’ choices, rats weighted wins more than losses, as indicated by a higher win-stay, and lower lose-shift probability. This asymmetrical learning strategy enabled rats to remain with the correct action, while discounting the influence of rare losses. Further, male rats were more impacted by their uncertainty history when making win-stay decisions compared to females. Hence, we found sex-specific contributions of these latent computations in modulating behavior. We overall demonstrate that asymmetrically weighting wins and losses could form an important behavioral strategy when adapting to ongoing changes in reward and uncertainty history.

The online version contains supplementary material available at 10.1038/s41598-026-37554-3.