Is multitasking efficient? Different metrics, different conclusions

Area of Science:

• Cognitive Psychology
• Human-Computer Interaction
• Performance Science

Background:

• Multitasking, the concurrent execution of multiple tasks, often leads to performance deficits.
• Despite known costs, individuals frequently engage in multitasking for personal and professional reasons.
• Previous research primarily focused on central processing limitations, overlooking potential benefits of parallel peripheral processing.

Purpose of the Study:

• To investigate whether subjective impressions of multitasking efficiency align with objective measures.
• To explore potential benefits of parallel peripheral task processing during overlapping task execution.
• To compare Time on Task (ToT) in overlapping versus sequential dual-task conditions.

Main Methods:

• Two experiments were conducted comparing overlapping and sequential dual-task conditions.
• Experiment 1 used a Psychological Refractory Period (PRP) paradigm with distinct task sets.
• Experiment 2 employed identical task sets to intensify between-task interference.

Main Results:

• Both experiments demonstrated significantly shorter Time on Task (ToT) in the overlapping dual-task condition compared to the sequential condition.
• Minimal evidence of compensatory effects was observed.
• The findings indicate that parallel peripheral processing can offer benefits in multitasking scenarios.

Conclusions:

• Assessing multitasking efficiency requires considering both central processing costs and peripheral processing benefits.
• Total time on task (ToT) is a crucial metric for a comprehensive evaluation of multitasking performance.
• The choice of evaluation metrics significantly impacts the understanding and justification of multitasking efficiency findings.