Virtual Reflections on a Dynamic 2D Eye Model Improve Spatial Reference Identification

TL;DR

This paper addresses the challenge of conveying spatial references with 2D eye models by introducing mirror eyes, a dynamic eye model augmented with a reflection-like overlay that shows the attended region. The approach combines pupil-centered eye movement with a scene-centric mirror cue to simplify spatial reference identification, and it is evaluated against pure eye models and purely reflective overlays in a group task. Results show higher identification accuracy for mirror-eye conditions without slowing responses, and user experience is notably enhanced, supporting a synergistic benefit of the combined cues. The work suggests practical implications for human-machine interaction and paves the way for extending mirror-eye cues to physical embodiments such as robots with movable heads.

Abstract

The visible orientation of human eyes creates some transparency about people's spatial attention and other mental states. This leads to a dual role for the eyes as a means of sensing and communication. Accordingly, artificial eye models are being explored as communication media in human-machine interaction scenarios. One challenge in the use of eye models for communication consists of resolving spatial reference ambiguities, especially for screen-based models. Here, we introduce an approach for overcoming this challenge through the introduction of reflection-like features that are contingent on artificial eye movements. We conducted a user study with 30 participants in which participants had to use spatial references provided by dynamic eye models to advance in a fast-paced group interaction task. Compared to a non-reflective eye model and a pure reflection mode, their combination in the new approach resulted in a higher identification accuracy and user experience, suggesting a synergistic benefit.

Figures (8)

• Figure 1: Illustration of an eye model that displays a mirror image of an attended area as a reflection-like overlay on its pupil and iris.
• Figure 2: Illustration of the spatial shift for pupil and mirror image location as described by Equations \ref{['eq_my']}-\ref{['eq_ex']}. Top: All centers are aligned. Bottom: A small rightward shift of the pupil is accompanied by a larger leftward shift of the mirror image.
• Figure 3: Experiment procedure with duration estimates for individual steps.
• Figure 4: Schematic of the experimental setup: (a): The diagram shows the distance of the three participants from the display and their respective positions. The participants had the freedom to move their bodies or head while in their positions. (b): The illustration depicts the size and height of the visual stimuli presented as cues on the gray display.
• Figure 5: Box plots showing the distributions of accuracy scores across conditions for single condition blocks (left) and mixed condition blocks (right).