By Indre Viskontas, Ph.D., University of California, San Francisco
The popular misconception is that when we’re texting and driving or multitasking in some other way, we’re doubling up on our efficiency. The truth is that we’re not. We’re switching our attention between tasks—and every time we make a switch, we pay a price.
It’s so Easy to Multitask
Our lives have become so convenient with email and world maps at our fingertips. You can drop down into virtually any city. While you’re catching a ride to a popular local restaurant, you sign up for an exercise class, check international newspaper headlines, book a hotel room, and have a conference call with your boss.
It’s become so easy to do these things that many of us are prone to over-scheduling our lives, knowing that just because we’re not in the office, it doesn’t mean that we can’t still accomplish work-related tasks. This bad habit leaves us breathless, putting us in a position in which we have to do more than one thing at the same time. We can’t just get lost in thought at a stoplight, so many of us—although it’s illegal in many places—can’t resist the temptation of glancing at our smartphones as the seconds tick by interminably slowly.
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And yet, several studies show that texting, checking email, or being otherwise engaged with our phones while driving renders us just as impaired as having had a few drinks. Depending on the study, texting has at least as big impact: reportedly the likelihood of getting into an accident is a four times larger risk than drinking four beers.
In one study, for example, drivers’ reaction times decreased by 13 percent if their blood alcohol level was at the legal limit and 21 percent if they were high on cannabis.
In one study, for example, drivers’ reaction times decreased by 13 percent if their blood alcohol level was at the legal limit and 21 percent if they were high on cannabis. Even during a hands-free call, reaction times decreased by 27 percent. Texting caused a decrease of 37 percent and making a call plummeted reaction times by 46 percent.
This is a transcript from the video series Brain Myths Exploded: Lessons from Neuroscience. Watch it now, on Wondrium.
You might think driving is complicated, but surely you can walk and text. Not so, says a study published in the journal Gait & Posture showing that people who were texting while walking deviated off course 61 percent more often than those who weren’t texting. Another study showed that people talking on their cell phones while walking missed important cues in the environment—like a clown riding a unicycle.
Why is texting so disruptive to our ability to navigate either on two feet or four wheels? Why do we think it’s safe, despite the statistics indicating otherwise?
Part of the answer is based on a popular misconception that when we’re texting and driving or multitasking in some other way, we’re doing two things at once—doubling up on our efficiency. But the truth is that we’re not: We’re switching our attention between tasks, and every time we make a switch, we pay a price.
Just like many of our cognitive biases, our memories, or the unconscious processes that shape our behavior, our intuition is not an accurate judge of how well we are switching between tasks.
Being Busy is not the Same as Being Productive
We’re often impressed by how much busy people can accomplish. For many of us, the ability to squeeze more tasks into our day by doubling up on them is a source of pride, rather than shame.
But people who multitask more often—who consider themselves particularly good at it—are actually worse at it than the rest of us.
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In one study, researchers from Stanford University asked their student participants to report on their frequency of multitasking using different media. That is, how often do they report watching TV, texting, or listening to music while working on their computers? Based on those self-reports, the researchers divided the students into two groups—heavy multitaskers and light multitaskers.
Then, they tested these students on their ability to perform several cognitive tasks, including tests of task-switching ability. Common sense would predict that heavy multitaskers would show a benefit of practice on task switching since they spend so much time doing it.
The heavy multitaskers were actually worse at the task-switching tests than the light multitaskers. They were more easily distracted by irrelevant cues, and their ability to hold more than one thing in mind was worse than the students who were less likely to do two things at once.
But the authors instead found a paradox. The heavy multitaskers were worse at the task-switching tests than the light multitaskers. They were more easily distracted by irrelevant cues, and their ability to hold more than one thing in mind was worse than the students who were less likely to do two things at once.
The authors conclude that heavy multitaskers are less able to filter out distractions from the environment. They have more trouble ignoring intrusive memories and, most surprising of all, they are less able to suppress the interference from a rival task when asked to focus on a target one. That is, they are worse at switching between tasks.
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In another study, from the University of Utah, 70 percent of participants reported that they were above average at multitasking. But when asked to memorize a sequence of letters while also doing math problems, those who reported multitasking most often in real life performed the worst. The top 25 percent of performers were also the ones who reported multitasking only sparingly in daily life.
What we don’t know yet is whether this impairment is the chicken or the egg. Does multitasking lead to a greater susceptibility to distraction and a decrease in the ability to control your attention? Or are people who are more distractible more likely to spend time trying to do two things at once?
We might see some hints in the traits of heavy multitaskers. That is, what else characterizes people who report multitasking often, and who think they are particularly adept at it? For one, they’re also more likely to be impulsive and to be labeled as sensation seekers—people who take more risks to get novel and intense experiences. It might be true that people who have shorter attention spans, to begin with, gravitate toward multitasking.
But regardless of which way the arrow points, the increasing availability of multiple media at our fingertips is only going to make this problem worse. That is, the more people succumb to the growing temptations to multitask, the more likely we’re going to see adverse effects on their ability to focus on challenging tasks.
We are Expected to Multitask
For many of us, the bigger issue is not just that we find it difficult to resist the temptation to entertain ourselves while we’re at a stoplight or walking along the street. The problem is the demand placed on us to always be available, to respond to emails and texts immediately, to fit a busy work schedule and family and friend time into a very short day—all this leaves us with is a few opportunities to spend a significant amount of time doing only one, focused thing.
Multitasking, in the real world, isn’t just about listening to music while we work on a project. Instead, it’s what society demands of us, now that we’re so easily contacted and connected. We can’t avoid it altogether.
But too often we let all these demands distract us from important activities that require a maximum of focus, leaving a trail of unfinished projects and unfulfilled dreams in our wake.
As a personal example, checking and responding to emails, making grocery lists, rearranging the living room are all things that I do when I’m unconsciously avoiding working. My husband can tell what kind of day I’ve had if he walks into a living room that he barely recognizes. It’s become a bit of a joke. The more frequently we are distracted by a new email or an unfinished chore, the harder it is to resist the temptation.
I don’t like to use the term addiction to describe what’s happening here because addiction is complex and should, in my opinion, be reserved for situations involving drugs that create physical symptoms of withdrawal. But multitasking does resemble addiction in one way—the more we do it, the more we seem to be tempted to do it again.
Our brains are creatures of habit. If you do the same thing over and over, the networks of neurons that are involved in that task get strengthened and fire more efficiently. This means that the next time you do that task, your brain’s activity will be slightly more fine-tuned. Like ski tracks on a hill, the more times the same path has been skied on, the deeper the ruts and the faster the track. But it’s also harder to take a different track because now you need to overcome the rut.
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By the same token, when you multitask, your brain doesn’t necessarily know which task is the important one. It’ll gravitate toward the easy, more sculpted track. If you’re doing two tasks, one of which is more ingrained, you’ll find your mind drifting back to that one rather than paving a new track. Checking email, which just requires the highly practiced task of reading, is easier than coming up with a genius new idea for a book.
The Mixing Cost
Even putting aside the decreased resources that we can spend on each task, every time we switch our attention from one task to another, we pay a price. Sometimes the price is small, and we can corral our attention back fairly easily. Often, we’re pretty quick at making the switch. But sometimes the cost is bigger than we think. Instead of a switch cost, we pay a price for mixing the two cognitive tasks—called a mixing cost.
The mixing cost is a measure of the extent to which the previous task intrudes into the current one.
The mixing cost is a measure of the extent to which the previous task intrudes into the current one. If you’re switching between checking email and preparing a presentation, the mixing cost can be pretty expensive, as you keep thinking about your emails—even though you should be thinking about your talk. We then fall into a trap of wasting too much time, then having even less dedicated time to do the thing that we were supposed to be doing.
Which brings us to the question of whether training can improve multitasking ability. The answer is yes—kind of. Though just multitasking itself might not do it, you need to have a strategy of how to get better at it. Usually, the strategy is to practice each task on its own before putting them together.
Brain imaging studies of this sort of multitask training show that the networks involved get more efficient—just as we would expect—rather than seeing a pattern in which new regions are recruited. We also see an increase in the speed of processing in the prefrontal cortex, underlining this increase in efficiency.
But multitasking the way most of us do it—alleviating the boring nature of one task, say driving, with a more stimulating bit of entertainment, say cell phone use—reduces our performance and our learning of the hard task. There are some serious consequences to this kind of habit, as attested by the number of accidents caused by distracted drivers.
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Common Questions About the Dangers of Multitasking
Studies now show that multitasking can actually damage the brain. As the brain can primarily focus on one thing at a time, keeping track of multiple things at once or accepting multiple streams of information can lead to decreased productivity and distraction from the task at hand. In some studies, it was shown that multitasking can even lower your IQ.
Multitasking is directly related to both anxiety and depression.
The human brain cannot actually multitask. It is just focusing on one thing at a time but shifting between them quickly, leading to the myth that they’re doing more than one thing at once. Try reading and listening to a lecture at the same time. You will notice blank spots as you shift between the information you receive from each task.
Studies reveal that the ability to multitask is essentially a myth. You can increase your ability to juggle things, but even with juggling, each hand is doing only one thing at a time in order. Keeping lists and grouping like tasks together can help you generalize for similar tasks. Constantly learning new information helps you prepare for new problems as well.