# Dream content and slow waves benefit prey against predator in a video game confrontation

## TL;DR

This study explores how sleep and dreams help people perform better in stressful situations resembling being prey in a video game.

## Contribution

The study shows that slow wave sleep and game-related dreams improve performance in prey-like scenarios.

## Key findings

- Prey participants' scores improved with slow wave activity during naps.
- Dreams related to the game predicted better performance in prey roles.
- Heart rate variability during the first round correlated with score gains in prey participants.

## Abstract

Every studied animal species exhibits some form of sleep, a state evolved under the sustained influence of prey and predator behaviors. Dreams have been proposed to have evolved as offline mental simulations able to warn against impending threats from the environment, such as predators. To assess how the ecological roles of prey and predator interact with sleep and dreaming, we used a first-person shooter game as a proxy for predator-prey confrontations. Electroencephalographic (EEG) and electrocardiographic (ECG) signals were simultaneously recorded from 30 human adult pairs while (1) playing a video game round against each other, (2) taking a nap, (3) reporting dreams and/or thoughts, and (4) playing another round. We found that the participants in the prey role were highly affected by sleep and dreaming. Their score gains were positively correlated with slow wave activity during the nap, with how much the dreams were related to the game, and with heart rate variability during the first round. In contrast, no significant correlations were found for participants in the predator role. The results suggest that slow wave activity and task-related dream content predict the post-sleep performance of individuals under stressful, low-agency, prey-like situations.

The online version contains supplementary material available at 10.1038/s41598-026-42759-7.