Perception of Emotions in Human and Robot Faces: Is the Eye Region Enough?

TL;DR

This study examines how robot face appearance and visible face regions influence human emotion perception, revealing that full faces enable better recognition, but eye-region visibility affects recognition accuracy depending on robot design.

Contribution

It provides new insights into how face region visibility and robot appearance impact emotion recognition in human-robot interaction.

Findings

Full-face robot expressions are comparable to humans in emotional clarity.

Emotion recognition declines when only the eye region is visible.

More human-like eye features improve emotion recognition in limited face views.

Abstract

The increased interest in developing next-gen social robots has raised questions about the factors affecting the perception of robot emotions. This study investigates the impact of robot appearances (humanlike, mechanical) and face regions (full-face, eye-region) on human perception of robot emotions. A between-subjects user study (N = 305) was conducted where participants were asked to identify the emotions being displayed in videos of robot faces, as well as a human baseline. Our findings reveal three important insights for effective social robot face design in Human-Robot Interaction (HRI): Firstly, robots equipped with a back-projected, fully animated face - regardless of whether they are more human-like or more mechanical-looking - demonstrate a capacity for emotional expression comparable to that of humans. Secondly, the recognition accuracy of emotional expressions in both humans and robots declines when only the eye region is visible. Lastly, within the constraint of only the eye region being visible, robots with more human-like features significantly enhance emotion recognition.