Eye Tracking to Evaluate the Effects of Interruptions and Workload in a Complex Task

Area of Science:

• Human-Computer Interaction
• Cognitive Psychology
• Ergonomics

Background:

• Interruptions negatively impact performance in complex tasks.
• Effective display design is needed to mitigate interruption effects across workload levels.
• Understanding post-interruption attentional states is crucial for adaptive display adjustments.

Purpose of the Study:

• To investigate the impact of interruptions on user performance and eye movements under varying workload conditions.
• To determine how workload levels influence attentional allocation following an interruption.

Main Methods:

• Utilized an emergency dispatching simulator with a visual monitoring task and auditory interruptions.
• Manipulated workload by adjusting the number and rate of emergency vehicle changes.
• Collected eye-tracking data, task performance metrics, and subjective workload ratings (NASA-Task Load Index) from 41 participants.

Main Results:

• High workload significantly degraded primary task performance and altered attention allocation post-interruption.
• Participants in high workload conditions exhibited narrowed and slower scan patterns after interruptions.
• These changes in scan patterns were not observed under low workload conditions.

Conclusions:

• High workload exacerbates the negative effects of interruptions on user performance and eye movements.
• Users in high workload environments demonstrate difficulty in rapidly scanning displays immediately after an interruption.