Exploring the Role of Pupil Dilation and Blink Rate in Perceived Workload in Collaborative Virtual Reality

This study investigates the relationship between eye-tracking metrics—specifically blink rates and pupil dilation—and subjective workload as measured by the SIM-TLX questionnaire in collaborative Virtual Reality (VR) tasks. Sixty-eight participants, divided into 34 pairs, performed a pick-and-place puzzle task across two distinct VR scenarios: a closed-room workspace condition (voice-only communication with no visual contact) and an open-room workspace condition (avatars and task-space visibility). Blink rates and pupil dilation were recorded continuously during the tasks, while cumulative workload was assessed post-task using the SIM-TLX. Results revealed significant differences in blink rates and pupil dilation between the two scenarios, with higher blink rates and larger pupil dilation observed in the closed-room condition, indicating higher cognitive workload. Furthermore, strong correlations were found between the physiological metrics and SiM-TLX scores, demonstrating that blink rates and pupil dilation serve as reliable, real-time indicators of perceived workload in collaborative VR environments. These findings pave the way for the development of adaptive VR systems that utilize eye-tracking data to monitor and manage cognitive workload in collaborative tasks.