Multitasking: why the brain doesn't really do two things at once and what you lose when you try

In short

Multitasking, in the sense of doing two tasks that require attention at the same time, is largely a myth. The brain switches quickly between tasks, and every switch uses up time and mental energy. Research shows that people who switch often between tasks make more mistakes, work more slowly and feel more tired at the end of the day. The alternative is monotasking: a single important task, in a protected block of time, with interruptions gathered at set times.

What multitasking really means

It's worth making an important distinction:

• automatic tasks + one task that requires attention: you can walk and talk on the phone, because walking is automatic;
• two tasks that require attention: writing an email and following a meeting, for example, can't truly be done at the same time.

In the second case, the brain does what researchers call task switching: it moves its attention from one task to another, many times a second or a minute. We have the impression of parallel work, but it's a very fast sequence.

The cost of switching between tasks

Every switch requires a few invisible operations:

1. switching off the rules of the previous task;
2. loading the rules of the new task;
3. remembering where you left off.

Cognitive psychology studies, including those by David Meyer and his colleagues, have shown that these switches can significantly reduce productivity, especially on complex tasks. The individual losses are fractions of a second, but they add up over a day with hundreds of switches.

Attention residue

Researcher Sophie Leroy described the phenomenon called attention residue: when you move from task A to task B, part of your attention stays with A, especially if A wasn't finished. You work on B with a divided mind.

You don't just lose the time of the switch. You also lose part of the quality of your thinking on the next task.

Why multitasking is tiring

Constant switching keeps the brain in a state of alert. The result, at the end of the day:

• the feeling that you've been busy all the time, but finished few things;
• difficulty concentrating in the evening, even on a film or a book;
• irritability and impatience;
• more small mistakes, like "I forgot the attachment";
• the need for continuous stimulation, for example checking your phone.

Over time, the habit of switching often can make sustained concentration harder. The brain gets used to the rhythm of interruptions.

The "I'm good at multitasking" myth

Many people consider themselves good at multitasking. A well-known Stanford University study, led by Clifford Nass, observed that people who did a lot of media multitasking performed, on average, worse at filtering out irrelevant information and at switching between tasks than those who did less.

The likely explanation: multitasking gives us a feeling of productivity and stimulation, not necessarily better results. The feeling of efficiency is not the same thing as efficiency.

When it's fine to do several things at once

• when one of the activities is automatic: walking, washing up, driving a familiar route, with attention;
• when the tasks are very simple and mistakes don't cost anything;
• when you listen to familiar instrumental music while you work, if it helps you.

The problem appears when you mix tasks that require thinking, decisions or attention to detail.

Monotasking: the practical alternative

One important thing at a time

Choose the main task for the next hour and close everything that isn't related to it: tabs, apps, notifications.

Protected time blocks

Plan 60–90 meeting-free minutes for work that requires thinking. Put them in your calendar like any other meeting.

Batch your interruptions

Messages and email can be checked at set times, for example every hour or three times a day. Your replies will be just as good, and your attention won't be fragmented.

Write down what distracts you

When an idea comes up or you remember something to do, write it on a sheet of paper and go back to the task. You don't have to solve everything immediately.

Close tasks before moving on

If you have to stop halfway, write two lines about where you left off and what the next step is. This reduces attention residue.

Meetings without laptops

In important meetings, a closed laptop and a phone face down improve both attention and the quality of the discussion.

Multitasking at the office: what teams can do

• clear rules about what "urgent" means;
• meeting-free intervals, shared by the whole team;
• realistic expectations about response times to messages;
• leaders who set the example by not doing other things during meetings.

A team that works in blocks of concentration usually produces more, with less fatigue.

How NeuroFit complements a concentration routine

After days with many switches, many people feel that their mind is still "buzzing", even after closing the laptop. NeuroFit by Emmanuel CliniX, in Bucharest, offers an hour in which your attention is no longer divided: no phone, no notifications, in an armchair.

• Focus (tPBM, neurofeedback, tDCS): for periods when you need sustained concentration;
• Reset (taVNS, tPBM, CES): after weeks with many interruptions and a fast pace.

Each circuit is set after a safety screening. The first experience costs 190 lei, and if you subscribe within 7 days, the amount is deducted from your membership. Bookings: +40 790 099 070.

NeuroFit is brain wellness, not medical treatment.

A one-week experiment

1. Choose a 60-minute block every day for a single important task.
2. Put your phone in another room during this time.
3. Check email only at three set times a day.
4. Write down in the evening how you felt and how much you finished.
5. At the end of the week, compare it with an ordinary week.

Frequently asked questions

Can the brain do two things at once?

It can combine an automatic activity with one that requires attention, for example walking and a conversation. Two tasks that both require attention aren't done at the same time, but through fast switches between them.

Why do I get more tired when I multitask?

Because every switch between tasks uses up mental energy, and hundreds of switches a day keep the brain in a state of alert. The result is fatigue, irritability and more mistakes.

What is monotasking?

It's the practice of working on a single important task at a time, in a protected block of time, with notifications switched off and interruptions batched at set times.

Is music while working a form of multitasking?

Familiar instrumental music can help some people concentrate. Music with lyrics or podcasts, however, compete with tasks that involve language, such as writing or reading.