Confession time: in the course of writing this article, I’ve checked Facebook, HipChat, Skype, and Reddit. Instagram twice. I’ve switched to two other tasks and sent four emails. No, the irony is not lost on me.
Distractions are everywhere, and blocking them out can feel impossible. New emails never stop coming, along with questions and requests from colleagues. We jump between tasks on our to-do lists and respond to notifications in an attempt to juggle all of our responsibilities simultaneously, telling ourselves we’re getting more done by tackling two (or more) things at once.
Many people know that focusing on one task at a time leads to much better results, yet we still find ourselves multitasking in an attempt to check items off our to-do lists twice as fast. Why is multitasking so seductive? And what can we do to make our propensity to indulge distractions work for us, instead of against us?
Let’s make like Miss Frizzle and delve deep into the brain to find out how attention works, what happens when we try to multitask, and what we can do to make our desire to do too much at once work to our advantage.
Neuroscience 101: This is Your Brain on Multitasking
Trying to multitask actually changes the way your brain works. When you focus your attention on something, it activates part of your mind’s motivational system: the prefrontal cortex, which wraps around the front of your brain.
When you’re focused, both the left and right sides of the prefrontal cortex work in tandem. But when you multitask, they attempt to work independently. Even though it feels like you’re doing two things simultaneously, you’re actually switching between the two sides of your prefrontal cortex. This switch takes a fraction of a second, but those microseconds add up: it actually takes you up to 40% longer to complete the same tasks than if you were to tackle them separately.
Not only that, switching between tasks drains your cognitive resources, making you more prone to mistakes. Your working memory, which is responsible for reasoning, decision making, and learning ability, has a limited capacity. It’s like a muscle that can only lift so much weight and do so many reps before it needs to rest and recover. Complex tasks have a higher cognitive load, and are more taxing on your working memory. Trying to do multiple complex tasks at once (say, making a phone call while driving), is simply too much for your brain to handle, and you’re more likely to make mistakes. When you add a third task (like following your GPS directions) you make three times the number of errors than when you’re trying to do two things at once.
You’re only able to do several things at once when the cognitive load of each task is low; for example, going for a walk while eating a snack and listening to your favorite podcast.
Your Brain’s Anti-Distraction System
Focusing your attention takes more than channeling your brainpower into a single goal; it also involves blocking out all the other stimuli that’s trying to distract you. After all, if you’re not able to filter out what’s irrelevant to your current task, all those distractions will slow you down.
When you’re focused, your brain is functioning differently even at the neural level. The messages your neurons send each other when you’re trying to pay attention are both more intense and more clear — like they’re in a noisy room, trying to shout a single, simple message to one another.
In addition to your neurons communicating more forcefully, key sections of your brain synchronize with each other. Lines of communication open up between the different regions of the brain required for attention, and unrelated signals are suppressed in order to prevent distractions from getting through.
Multitasking Fries Your Brain
You may think staying focused and blocking distractions causes your brain to work harder, but in fact the opposite is true. Switching between tasks makes your brain eat up more glucose, making you feel exhausted and disoriented even after a small amount of multitasking.
Moreover, recent studies show multitasking has a physical, possibly permanent impact on the brain’s structure. Heavy media-multitaskers have smaller gray matter density in the anterior cingulate cortex, which helps regulate both automatic bodily functions like blood pressure and heart rate, as well as rational cognitive functions like decision making, empathy, impulse control, and emotional regulation.
Multitasking causes new information to get stored in the wrong part of the brain. It compromises your short-term memory. Just knowing that there’s an unread email in your inbox can lower your working IQ by 10-15 points, effectively turning you into the cognitive equivalent of an 8-year-old.
Not only is multitasking bad for your brain, it’s bad for your body. It increases the stress hormones cortisol and adrenaline, which can result in narrowed arteries, increased blood sugar, and suppressed immune systems, among other health problems.
Given all of these concerning downsides, why do we still spend so much time multitasking?
The Hormone High of Distraction
Even though you need it to focus, your prefrontal cortex craves novelty. New stimuli cause a surge of endogenous opioids to the reward-seeking parts of the brain. It feels good to indulge in distractions. This not only makes it incredibly difficult to focus on a single complex task, it makes you more likely to complete a dozen simpler, more inconsequential tasks like responding to email or making phone calls, rather than tackle bigger, more significant projects.
Every time you respond to an email, post a Tweet, or send an instant message, you get a shot of hormones directly to the pleasure center of the brain that can be incredibly addictive. In fact, in laboratory studies, rats that could press a bar to send an electrical impulse directly to this pleasure center were so absorbed with pushing the lever that they ignored food and sleep to the point of starvation and death. That’s how powerful this addiction can be.
Exceptions to the “No Multitasking” Rule
In spite of all these compelling reasons to avoid multitasking at all costs, there are a few situations where juggling tasks is actually beneficial.
One example: exercise. Physical activity boosts circulation to your brain, delivering oxygen and other nutrients necessary for optimum mental performance. It also produces chemicals that improve memory, problem solving, and decision making skills, while releasing hormones that boost attention, motivation, and focus. In a recent University of Florida study, participants cycling on stationary bikes completed a series of tasks of varying difficulty. Easy tasks actually caused participants to cycle faster, with no detriment to their cognitive ability. Both their brains and bodies were working efficiently on simultaneous tasks. As tasks increased in difficulty, their cycling speed did slow down, but even the most difficult mental work only set them back to their original cycling speed.
Another instance where multitasking can improve your performance is during tedious tasks that are low cognitive load. Letting your mind wander while you wash the dishes or fold laundry fosters creative problem solving and aids effective decision making by allowing you to imagine the outcomes of different choices, or come up with a completely new alternative. Your brain is better at solving complex problems when it breaks away from the situation and comes at it from a different angle. (That’s why you always think of your best ideas in the shower, or while brushing your teeth.)
Lastly, a new type of multitasking is emerging in the digital age of information overload. “Continuous partial attention” involves mentally skimming several streams of incoming data simultaneously and gleaning only the relevant details from each. Imagine you’re working on a task while listening to music. and suddenly hear a specific word in a background conversation that catches your attention. Although you’re mainly focused on one central task, part of your brain is still attuned to the background. You’re simultaneously aware of multiple streams of information, sifting it all in the back of your mind and shifting your attention to whichever stream is most urgent or interesting. Modern technology gives us access to incredible amounts of incoming data, and we’re using this type of multitasking to quickly pull helpful information from a wealth of available resources.
Debunking The Multitasking Myth
In the late ’90s and early 2000s, with the rise of PDAs and other personal productivity devices, we embraced multitasking as a way to keep pace with the new speed of business. We highlighted our ability to juggle tasks on resumes, and bragged about how many assignments we were able to complete at once. Multitaskers were seen as efficient, high-performing employees.
Now we know the truth: multitasking impairs our work. It slows us down, we make more mistakes, and it wears us out both mentally and physically. But we also know the few key situations in which multitasking can provide some real benefits, so we can indulge our brain’s appetite for distraction without sacrificing our mental clarity or compromising our intellect.