The eyes show it: Exploring eye behavior and impact on human mental state during task interruption

• Both gaze and paragaze can indicate task transitions due to interruption or not • Both gaze and paragaze can reflect task change due to interruption • Only strong emotional interruption affects eye behaviors afterwards • Task type significantly affects the time to attend an interruption • Unproportionally increased completion time for low and high cognitive load tasks One technology adoption outcome is ever more frequent task interruptions, which makes interruption management a central human computer interface design problem. Studies on interruption often focused on the link between interruptions and genesis of error and eye gaze to validate associated task cues engagement. How eye behaviors reflect load type and level changes between primary and interrupting tasks and how emotional interruptions impact mental state in primary tasks – factors that contribute to cognitive processing – remain unanswered. In this study, we analyzed performance metrics and eye behaviors from 18 participants while they completed an uninterrupted and interrupted roleplay task. Our results reveal that although interruption notification could affect the time to attend to an interruption, high cognitive load resulted in a detrimental impact on completion time and low cognitive load led to time reset for primary tasks. No existing evidence suggests that affect type influences the time metrics, however, high arousal and valence induced by interruptions altered eye behavior upon returning to the primary task, indicating less visual information taken and under a high load level, which showed evidence of the impact of affective interruption for the first time. Noteworthily, the eye behaved differently at interruption beginning compared with the end and uninterrupted task transitions, indicating the feasibility of including eye behavior for interruption estimation. Overall, these results are the first experimental evidence for theories that interruption can cause high mental load, posit extra mental effort, forgetting primary tasks and behaviors being directed by the current most active goal.