Checking Slack while sitting in an online meeting.
Replying to an incoming chat message halfway through writing an email.
Taking a phone call while putting together a document.
For busy professionals especially, working on several tasks at once—“multitasking”—has probably become part of everyday life.
At first glance, it looks like an efficient way to work, getting through a lot in limited time.
Yet according to research in cognitive psychology, when we handle several tasks that require attention, we are not necessarily processing them all fully “at the same time.”
In reality, we are often rapidly switching our attention and mental rules from one task to another.
And this “switching” itself comes at a cost.
The Brain Switches Rapidly Rather Than Processing in Parallel
In psychology, this phenomenon has long been studied as task switching.
In 2001, Professor David Meyer and colleagues at the University of Michigan conducted experiments in which young adults switched between different tasks, such as solving math problems and classifying geometric shapes.
They found a “switch cost”: compared with continuing the same task, switching to a different task required extra processing time.
What is more, the more complex the tasks, the greater the time cost of switching.
In other words,
“going back and forth between two tasks makes you twice as efficient”
is not necessarily true.
Even if the loss each time is small, switching dozens of times between email, Slack, meetings and documents means that small burden keeps repeating.
Your Previous Task Can “Linger in Your Mind”
Even more interesting for professionals is research on “attention residue.”
In an experiment published in 2009 by Professor Sophie Leroy, now at the University of Washington Bothell School of Business, it was reported that even after people switch to a different task, part of their attention can remain on the previous task.
In particular, when people moved on from a task they had not yet finished, they could not fully detach their attention from it, and their performance on the next task declined.
For example, a Slack message arrives while you are working on an important document.
You reply and go back to the document, but
“Was that reply okay?”
part of your mind is still thinking about Slack.
Even though you are physically back to working on the document, your attention may not have fully returned.
Is It Fine If You Are Good at Multitasking?
“I multitask all the time, so I’m used to it.”
Some of you may feel this way.
However, in a study published in 2009 by a research team at Stanford University, the cognitive abilities of people who routinely use many media at once were compared with those who do not.
The results showed that, compared with light media multitaskers, heavy media multitaskers were more easily affected by irrelevant information and did not perform better on task switching either.
Of course, this study alone cannot establish a causal link such as “continuing to multitask lowers your concentration.”
Even so, it is an interesting result showing that we cannot simply say “people who do many things at once also become better at switching”.
Single-Task Your Most Important Work
Of course, not every kind of “doing two things at once” is bad.
Combining simple work with another activity may not cause any real problems.
What deserves attention is repeatedly interrupting work that requires deep concentration.
Planning ideas.
Writing important documents.
Checking figures.
Making management decisions.
Truly understanding what someone is saying.
When you are doing this kind of work, try:
Turning notifications off for a while.
Closing your email and Slack.
Setting a time block, such as “30 minutes for this task only.”
Not doing other work during meetings.
Consciously setting aside single-tasking time like this may, in the end, make you more efficient.
Don’t Multitask Even When You Rest
And this is not just about work.
Social media on your commute.
YouTube while you eat.
Your phone while you watch TV.
Checking work chats during your break.
Even outside work, we are increasingly taking in several streams of information at once.
At La HEAD, in a calm, fully private room, you step away from your computer and phone, close your eyes, and receive slow, unhurried care not only for your head but also for your neck, shoulders and arms.
Getting lots of things done at once is not the only measure of working fast.
When you focus, focus on one thing.
And when you rest, rest without taking in the next piece of information.
Precisely because we live in an age of constantly juggling many things, consciously making time to do just one thing may be important for both your work performance and your own well-being.