Microgravity induces overconfidence in perceptual decision-making

TL;DR

This study investigates how altered gravity conditions in space analog environments influence perceptual decision-making, revealing that microgravity increases overconfidence without affecting actual performance, which has implications for human space missions.

Contribution

It provides novel evidence that microgravity specifically enhances subjective confidence in perceptual decisions, highlighting the need for automated decision support in space environments.

Findings

Microgravity increases subjective confidence in decisions.

Uncertainty affects confidence but not decision accuracy.

Altered gravity conditions influence perceptual decision-making processes.

Abstract

Does gravity affect decision-making? This question comes into sharp focus as plans for interplanetary human space missions solidify. In the framework of Bayesian brain theories, gravity encapsulates a strong prior, anchoring agents to a reference frame via the vestibular system, informing their decisions and possibly their integration of uncertainty. What happens when such a strong prior is altered? We address this question using a self-motion estimation task in a space analog environment under conditions of altered gravity. Two participants were cast as remote drone operators orbiting Mars in a virtual reality environment on board a parabolic flight, where both hyper- and microgravity conditions were induced. From a first-person perspective, participants viewed a drone exiting a cave and had to first predict a collision and then provide a confidence estimate of their response. We evoked uncertainty in the task by manipulating the motion's trajectory angle. Post-decision subjective confidence reports were negatively predicted by stimulus uncertainty, as expected. Uncertainty alone did not impact overt behavioral responses (performance, choice) differentially across gravity conditions. However microgravity predicted higher subjective confidence, especially in interaction with stimulus uncertainty. These results suggest that variables relating to uncertainty affect decision-making distinctly in microgravity, highlighting the possible need for automatized, compensatory mechanisms when considering human factors in space research.