The myth of multi-tasking.


Last month I was invited to speak to a group of young people brought together to create innovative road safety solutions for their peers.

The problem they are trying to solve is this:

  • 88% of young drivers admit to using their mobile phones while driving.
  • Texting is the most prevalent behaviour, at traffic lights (50%) and while driving (25%).
  • 25% of drivers check email, social media and the internet at the lights, and 15% do so while driving.

Consider that problem in light of these stats, (data from Queensland Government, Australia):

  • In 2013, there were 271 fatalities and 6,921 hospitalised casualties on Queensland roads. Distractions and inattention are known to have contributed to 19 fatalities (or 7.0%) and 1,343 hospitalised casualties (or 19.4%).
  • The two key influencers that drivers use to explain mobile phone use are the need to keep in touch with people and the pressure to respond to text and calls immediately.

I spoke about attention and multi-tasking and why it’s IMPOSSIBLE for most of us to multi-task (even though many of us think we can).

After I spoke, the session broke into groups to brainstorm powerful, emotional, and out-of-the box ideas to share and engage with their peers. I was involved in a similar campaign in 2015, and THIS was the result.

Here are some of the ideas I shared this year.

Your attention is like a flashlight.

Attention is what you choose to focus on. Or what you’re currently thinking about or concentrating on. It’s useful to think of attention as being like a torch or flashlight. In particular, the type of torch that has an adjustable beam of light. Like a beam of light, your attention,

  • is always on (but it’s not always pointing in the right direction, sometimes it drifts)
  • can be broad and diffuse, or narrow and focused
  • cannot SPLIT in two.

Imagine you’re driving a car. Like the beam of light, your attention could be external, broad and diffuse — perhaps scanning the patterns of traffic on a motorway deciding whether to stay in your lane. Or it might be tightly focussed and defined — you might be intently watching and waiting for a traffic light to change. Your attention could also be focussed internally on your own thoughts — perhaps a mental map to help navigate your journey. Or it could be narrowly and internally focussed — trying to remember a shopping list to pick up on the way home.

Whilst our attention is reactive — we respond to external stimuli such as the beeping horn — the key is to switch attention and selectively focus on what is appropriate (hint: this isn’t a text message that arrives when you’re driving!).

What happens when we multi-task distract ourselves when driving?

Talking on a mobile phone while driving is an ill-advised activity that many people believe they’ve mastered.

Sure, you can check Facebook while eating your lunch, or listen to music while walking the dog. But innate activities such walking, chewing, and breathing don’t require you to selectively shine your beam attention. Activities such as reading, tapping out a text message, or driving a car DO require attention.

Data gathered over a number of years by David Strayer, Professor of Psychology at the University of Utah and his team support this. They observed thousands of drivers as they approached a variety of intersections, and saw the majority of drivers who were talking on their phone failed to stop in accordance with traffic laws. And it didn’t matter if the driver was using a handheld or hands-free device — even with both eyes on the road and both hands on the wheel, drivers’ performance was impaired. (Interestingly, the same result isn’t seen when chatting to a front seat passenger, presumably they’re also focussed on the road, have a vested interest in driving safely, and change their behaviour according to road conditions.)

Talking on a mobile phone while driving is the classic example of multi-tasking gone wrong. Other studies have show the following happens:

  • riskier decision making – using a mobile phone while driving affects judgement and concentration
  • slower reactions – you generally react slower when using a mobile phone, particularly when you’re deep in conversation; you may take longer to respond to traffic signals or completely miss them
  • slower and less controlled braking – during a mobile phone call, your brake reaction time is slower, and you brake with more force and less control, resulting in shorter stopping distances between yourself and the car in front
  • not being alert to your surroundings – when using a mobile phone, you tend to spend less time checking your mirrors and what’s going on around you. This affects your ability to monitor and negotiate traffic safely.

Try this game to prove multi-tasking is impossible.

Many people don’t believe that the above research apply to them. They believe they’ve mastered multi-tasking.

Here’s a simple task to try with that shows how difficult it is to split your attention between two seemingly simple tasks (it’s guaranteed to generate a few laughs, as well as drive the point home!).

  1. Time someone while they recite the alphabet out loud (“A, B, C, D ….”)
  2. Time them to count backwards from 26 out loud (“26, 25, 24, 23 …”)
  3. Time them ‘multi-tasking’ as they alternate between the alphabet and counting e.g. “26, A, 25, B, 24, C, 23, D….”

Watch carefully and you’ll notice a number of things: they’ll make more mistakes, they’ll slow down, and they’ll probably become rather stressed (they’ll laugh, blush, or even refuse to finish!).

This is a clear example of what happens when we try to divide our attention (beam of light) between two cognitive (thinking) tasks. We can’t split our attention into two, instead we switch back and forward between the two tasks and performance in even the most simple tasks drastically deteriorates.

Splitting attention isn’t clever multi-tasking; it’s engaging in distraction.

What’s going on in the brain when it tries to multi-task?

The prefrontal cortex is the brain region responsible for choosing what to pay attention to, and for coordinating inputs from other brain areas. By scanning the prefrontal cortex of people while they multi-tasked, scientists at the INSERM in Paris found that when people focus on a single task, the right and left sides of the prefrontal cortex work together. But when people attempt to perform two tasks at once, the sides work independently.

Neuroscientist Etienne Koechlin lead researcher on this study says it demonstrates that while the brain can switch back and forth between two tasks,

“…we might be in great trouble when we try to juggle more than two tasks, simply because we have only two frontal lobes.”

Multitasking doesn’t just slow you down and increase the number of mistakes you make; it temporarily changes the way your brain works!

Other researchers who study attention say that effective multi-tasking is nearly impossible. Psychiatrist Edward M. Hallowell describes multi-tasking as a

“…mythical activity in which people believe they can perform two or more tasks simultaneously as effectively as one.”

I surveyed the the attendees at the CoLab meeting and asked them what percentage of the population they believed could effectively multi-task. Their answer of “about 50%” is in line with how most people respond. Unsurprisingly, most people place themselves in this skilled but mythical subgroup. The reality is very different. David Strayer has found only 2.5% of the population is able to multi-task.

For most of us, our brain simply isn’t capable of paying close attention to more than one complex task at a time.

My message is simple: put down the phone. (I can’t wait to see what the creative CoLab campaign comes up with!)

Parts of article were originally published in Active Memory.

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  1. Melissa on November 1, 2016 at 2:03 pm

    I’ve have a question that I’ve wondered about for a few years: is talking on a cell phone while driving more distracting than listening to music, talk radio or an audio book or podcast? I’ve just been perplexed about why we talk so much about talking on the cell phone while driving, but never about other ways we distract ourselves. Is it because listening to music, talk radio or an audio book / podcast is passive and a conversation is interactive, thus requiring more focus?

    To be honest, I find that I am most distracted when I’m in a silent car with just my own thoughts. I get to work and wonder how I got there because I was so stuck in my own head. And I get super involved in audio books and podcasts. But maybe that’s a personal problem 🙂

  2. Clay Ryan on November 3, 2016 at 5:33 pm

    Yes, multi-tasking is a myth for most. Although at one time, I was certainly in the super-tasker capable group whose focus actually increased in those multiple effort situations, I now know that this creates harm to the brain. (see Scientific American Mind articles)

    By continually practicing multi-tasking, you train the brain to divide its attention. This is not good. Simple as that.

    Also, just like being a ‘super’ athlete at a younger age, it is not sustainable over time.

    For me, I found out just how simple ‘dual tasking’ created a significant alteration in my breathing, heart rate, heart smoothness, and therefore, capacity when I first played a Biofeedback game called Dual Drive (Alive).

    When not controlling the car, all of my feedback breathing, heart rate, etc. parameters were perfect; once I started the 2nd task of driving the car, my previous perfect was 50% and chaotic.

    Such as it is in real life driving – or working. One task focus is what we do best.

  3. Denise Medved on November 5, 2016 at 1:15 pm

    Sarah — what, if any, difference do you know of between multitasking and multi-skilling — and how do each affect/involve the brain? In the fitness and movement world, we refer to multi-skilling as being able to do 2-3 different physical functions of one activity, a skill developed through practice: playing the violin for example, requires my left hand to play chords on the frets, my head and chin need to position the violin, my right hand needs to play the bow or pluck the strings….this would be called “playing the violin” yet it involves three or four different physical skills simultaneously and requires my brain to direct each of those physical and mental activities

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About Dr Sarah

I’m an Oxford University-educated neuroscientist, presenter of ABC Catalyst, director of The Neuroscience Academy, and author of The Women's Brain Book. The neuroscience of health, hormones and happiness.

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