MSS #102: Multitasking vs. Multiplexing: The Real Story Behind Your Brain's Limits

MSS #102: Multitasking vs. Multiplexing: The Real Story Behind Your Brain's Limits

21 Dec, 2024

🕒Read time: 3.5 minutes

🚀In a hurry? Cut straight to the heading “The Science of Context Switching” - reduced read time 1.4 minutes

We’ve all been there—juggling emails while on a call, or switching between work tasks and social media, thinking we’re multitasking pros.

But that’s an illusion: your brain can’t truly multitask.

Instead, it’s multiplexing, switching rapidly between tasks.

This week, we’ll uncover the difference between multitasking and multiplexing, explore the brain’s processing limits and reveal how context switching affects your productivity.

Multitasking vs. Multiplexing: The Key Distinction

There are lots of myths and stereotypes about multitasking, not least that those that can multitask are some type of super heroes. It’s not quite as it might seem to be though.

• Multitasking implies doing multiple tasks simultaneously. Strictly speaking this means you can work on ore than one task at the same time.

• Multiplexing, in the context of the human brain, is rapidly alternating focus between tasks. Your attention doesn’t split; it shifts, so you spend short bursts of time on each separate task, but switch so rapidly between tasks it may feel like you are working on more than one thing at a time.

While it may feel like you’re achieving more, each switch comes with a cost in mental effort and time.

Multitasking is strictly speaking a myth! We are not able to consciously work on more than one thing at a time.

The Brain's Limits: 7±2

Psychologists have long studied the brain’s working memory capacity, often cited as 7±2 items.

This means we can hold 5–9 distinct pieces of information in our short-term memory at any given time.

However, actively working on these items is another matter.

Your conscious brain can focus on only one thing at a time. The prefrontal cortex (conscious brain), which is responsible for decision making and attention, can only allocate it’s resources to a single task requiring conscious though. Attempting to split attention overloads the system.

When you “multitask,” you’re actually juggling tasks in sequence—not performing them simultaneously.

Multitasking is not possible - if your definition is consciously working on multiple projects at a time. What is really happening is we are holding 5-9 projects in our mind, but only working consciously on one of these at any time.

The Science of Context Switching

Context switching refers to the mental effort required to shift between unrelated tasks or topics. This is what happens each time we select one of those 5-9 projects we are holding in our minds.

Each switch demands cognitive energy to "reload" the new task’s context into your brain.

Research shows that it can take up to 23 minutes to regain full focus after switching to a different task.

This becomes even more challenging when moving between significantly different types of activities, such as analysing data and responding to emails. If we are switching between similar projects it takes less time to regain focus.

Why Context Switching Drains Productivity

Context switching is very inefficient, here’s why:

• Memory Reloading: Switching tasks means temporarily unloading information related to the first task, then reloading context for the next. This process creates delays and cognitive fatigue.

• Attention Residue: Part of your attention remains fixated on the previous task, reducing focus and efficiency on the new one.

• Increased Errors: Rapid task switching increases the likelihood of mistakes as your brain struggles to fully engage with either task.

If you add to this, unexpected interruptions as well, then our efficiency drops further.

The Cost of Multiplexing

Getting caught in multiplexing is not good.

It should not be a badge of honour, as it often is.

Here’s why.

• Efficiency Drops: Studies estimate a 40% reduction in productivity when frequently switching tasks.

• Mental Fatigue: Constantly shifting focus strains your brain’s cognitive resources, leading to quicker burnout.

• Reduced Creativity: Deep work and innovative thinking require sustained focus—something multiplexing can disrupt.

 We are in fact short changing ourselves by keep switching between different tasks and projects.

How to Minimise Context Switching

Ok, so what can you do about this – how can you reduce the likelihood your efficiency is going to take a persistent nose dive.

1. Batch Similar Tasks: Group tasks that require similar mental processes (e.g., responding to all emails at once).

2. Time Blocking: Dedicate uninterrupted blocks of time to specific tasks or projects to maintain focus.

3. Prioritise Deep Work: Identify high-priority tasks requiring deep concentration and tackle them when your energy is at its peak.

4. Turn Off Notifications: Reduce distractions by silencing alerts and setting boundaries for communication.

5. Use the Two-Minute Rule: Quickly complete small tasks instead of letting them pile up and interrupt your workflow later.

6. Do difficult tasks at your best time: We all know when we work best, if you are a morning, afternoon or evening person. Do the most demanding work, when your energy levels are naturally at a peak.

There is a lot we can do to improve our efficiency and effectiveness. Are you convinced enough to make some changes? If so, one big aspect you should start noticing is your spoken language and self talk. Do you keep praising yourself and others for multitasking? Do you ware multitasking as a public or mental medal of honour? Mind your language going forwards? Notice what you say publicly and to yourself and task praising focus on one thing at a time.

Summary

Recognising the difference between multitasking and multiplexing can help you work smarter, not harder.

By reducing context switching and focusing on one task at a time, you’ll unlock greater productivity and mental clarity.

Quick Recap:

• Multitasking is a myth; your brain engages in multiplexing, switching rapidly between tasks.

• You can hold 7±2 ideas in mind but work on only one consciously.

• Context switching slows you down, with an average recovery time of 23 minutes.

• Minimise context switching through batching, time blocking, and prioritising deep work.

See you next week. One more thought 👇

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That's it for this week. Thanks for reading, really hope this helped. Contact me if you think I can help you further at [email protected].

Happy thinking.