When we think of multitasking, most of us imagine a person doing multiple things at once — sending an email while talking on the phone or eating lunch while scrolling through messages. But is this really what happens in the brain?
Surprisingly, the term multitasking wasn’t originally used for humans. It first appeared in a 1965 IBM technical document — and it was about computers, not people. In that context, multitasking meant that a computer creates the illusion of performing several operations simultaneously by switching between tasks at extremely high speed.
Even before computers, William James in The Principles of Psychology (1890) discussed the limits of attention, arguing that a person cannot fully focus on two things at the same time. Although James didn’t use the word “multitasking,” his work laid the theoretical foundation for understanding divided attention.
The EPIC Model: How the Brain Manages Multiple Tasks
In 1997, Meyer & Kieras developed one of the first systematic models explaining how multitasking works in the human brain — the EPIC (Executive-Process Interactive Control) Model.
Main Findings of the EPIC Model:
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The brain includes a control system called Executive Cognitive Processes, which decides which task to perform and when.
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Just like computers, the brain doesn’t truly perform two tasks simultaneously; instead, it switches between tasks in milliseconds, giving the illusion of simultaneity.
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Every task has its own set of instructions (production rules). The brain stores and retrieves these rules as needed, allowing quick transitions but increasing cognitive demand.
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Perceptual and motor capacities (vision, hearing, speech, muscle movement) are limited — they cannot execute unlimited actions simultaneously.
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The brain prioritizes tasks, much like a computer’s operating system.
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In conclusion: the brain’s version of multitasking resembles computer multitasking, but it’s far less efficient and more error-prone.
The Cognitive Cost of Task Switching
While computers can switch between tasks nearly instantaneously with no fatigue, the human brain experiences time loss and cognitive load during each switch. This cost increases with task complexity. Every mental switch requires disengaging from one context and re-engaging in another — a process that drains attention and energy.
So, even though we feel like we’re doing more, our efficiency decreases with each additional task.
Experimental Findings: Buser & Peter (2012)
Researchers Buser & Peter (2012) tested how multitasking affects performance by asking participants to perform two different tasks under three different conditions:
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Fully Sequential – Tasks completed one after another in order.
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Forced Multitasking – Tasks performed simultaneously by requirement.
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Free Scheduling – Participants chose when to multitask or switch tasks.
Key Results:
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The Forced Multitasking group showed the worst performance.
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The Fully Sequential group showed the best results.
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The Free Scheduling group performed almost as poorly as the Forced Multitasking group — because when given freedom, people tended to manage time inefficiently and switch unnecessarily between tasks.
Gender Findings:
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In Forced Multitasking, men and women performed equally poorly.
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The popular belief that “women are better multitaskers” was disproved.
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Researchers suggested that this belief stems not from biology but from social expectations and daily role demands.
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Since many daily tasks are disproportionately assigned to women, they become practiced in task-switching, creating the illusion of superiority rather than a cognitive advantage.
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Interestingly, in the Free Scheduling condition, women multitasked less frequently than men.
Conclusion of the Study:
Multitasking significantly reduces overall efficiency, even when people believe it helps them manage more in less time.
(When your friend checks their phone while listening to you — are they truly hearing you? Think twice.)
Redefining Multitasking: The Science Behind the Myth
Multitasking is not doing several things simultaneously — it is the brain rapidly alternating focus between tasks.
Each shift happens within milliseconds, creating the illusion of parallel processing.
However, every transition consumes attention, working memory, and energy, resulting in mental fatigue and reduced performance.
While it might give the impression of productivity, multitasking is, in fact, a process that lowers cognitive efficiency.
In everyday life, this translates into more mistakes, longer completion times, and shallower focus.
Final Thoughts: The Mind Works Best One Step at a Time
The human brain was not designed to handle several attention-demanding tasks at once.
Unlike computers, our mental systems are bound by biological limits — emotional, perceptual, and attentional.
In a world that glorifies multitasking as a symbol of competence, it may be time to redefine productivity:
True efficiency comes not from doing more, but from doing one thing with full attention.
References
Buser, T., & Peter, N. (2012). Multitasking. Experimental Economics, 15(4), 641–655. https://doi.org/10.1007/s10683-012-9318-8
James, W. (1890). The Principles of Psychology (Vol. 1, pp. 381–384). Henry Holt and Company. https://doi.org/10.1037/10538-000
Meyer, D. E., & Kieras, D. E. (1997). A computational theory of executive cognitive processes and multiple-task performance: Part 1. Basic mechanisms. Psychological Review, 104(1), 3–65. https://doi.org/10.1037/0033-295X.104.1.3