Estimating Look-At Detection Thresholds

The human face and eyes provide crucial conversational cues about a person’s focus of attention. 
In virtual reality applications, avatar faces are typically simplified, and eye movements often neglected. 
This paper explores how VR users perceive the look-at direction of other avatars and estimates the range within which an avatar's averted gaze goes unnoticed.
Through two-alternative forced choice experiments, we investigate different gaze offsets to quantify thresholds for perceived gaze aversion across three conditions: gaze side (left/right), stimulus duration, and avatar distance.
Additionally, we assess the impact of averted gaze on social presence during interactions with an embodied conversational agent in a social game. 
A user study (N=40) revealed that social presence is significantly affected by averted gaze when noticed, and that detection thresholds are particularly impacted by stimuli duration and interactions between side and distance.
Our findings provide a foundation for understanding gaze perception in social virtual reality.