What All That Multitasking Is Doing To Your Brain—And Memory

New neuroscience research is showing how heavy multitaskers’ brains are different from everybody else’s.

Image courtesy of Flickr.

Though he runs a psychology and neuroscience lab at Stanford University, Anthony Wagner has never owned a smartphone. He only got a cell phone last year; “I want to finally be able to reach you on demand,” he recalls his wife saying. To keep his phone dumb is a conscious choice, he tells Thrive Global, but one not without costs: he gets lost driving more than he would otherwise, and he lacks the constant access to information that the 77 percent of Americans with smartphones have. But there are also gains: when he’s watching his daughter do gymnastics or his son skateboarding, he’s not feeling pulled to check Twitter; when he’s playing ultimate frisbee, he’s not feeling like he needs to check his email.

According to the research coming out of his Stanford Memory Laboratory and others, this also means that he’ll remember his kids’ handsprings and ollies more than if he was toting an iPhone, and he’ll remember his way around California better than if he were obediently following the voice of the Google Maps Lady like the rest of us. While the field is still young, Wagner and his colleagues are showing that multitasking — something of a default condition for internet-addled knowledge workers like this writer–isn’t just making us feel overwhelmed, it’s also handicapping our ability to remember the contents of our lives. But there’s hope. By recognizing this, human abilities like attention and recall don’t have to be eroded; they can be trained.

A key point for understanding this is that, inevitably, the human mind wanders. Even people who have accumulated 3,000 hours of meditation in their lives catch spontaneous thoughts popping into their heads every ten seconds, at least in one study. Attention, in a true sense, has to be actively sustained — whether you like it or not, you’re going to get off task, and you have to return to it. And heavy multitaskers, Wagner’s research indicates, just aren’t that good at it. “There are attentional gaps that we have to bridge, we have to maintain what our goals are,” Wagner says. “If you lose your attentional goals, you’re more likely to let in anything, including goal-irrelevant information.” You might be trying to write an article, but then a colleague messages you, and after replying, you should go back to writing the article, but instead you check Twitter.

The research suggests that this wandering has all sorts of downstream effects. Studies from Wagner’s lab and elsewhere find that people who are “heavy media multitaskers” — i.e., they report spending lots of time toggling between screens — actually do worse on tests of what researchers call “working memory,” or the ability to hold multiple objects of attention in mind, like the digits involved in doing math in your head. In a 2015 study, Wagner and his colleagues asked participants to view a collection of illustrations of everyday objects on a screen, and then say if any had moved, and heavier multitaskers were not only worse at identifying the right ones, they were also worse at a long-term memory task, where they were asked to identify which objects they’d seen before.

To Wagner, the reduced long-term memory looks like it comes from a lack of paying attention to things in the first place. “This is why we can have the same conversation or be at the same event, and have different memories,” he says. “As the experience is unfolding, what you’re selecting and what I’m selecting are different — it’s that mere act of selecting that has a powerful effect on what we’re consciously aware of.” Your experience largely depends on where you’re placing your attention, and same with what you can recall. “Essentially, what you put into memory is what you can pull out of it,” explains Melina Uncapher, a neuroscientist at the University of California-San Francisco and frequent collaborator of Wagner’s. “If you haven’t attended to it when you first experience it, no amount of magic will allow you to pull it back out,” she says. If you weren’t paying attention when you tossed your keys, then you don’t give your brain a chance to remember where you put them.

There’s also evidence that heavy multitaskers’ brains function differently than light multitaskers. This was demonstrated in a 2016 study, where 149 teens and young adults were asked to say if sentences were “congruent” or not when they flashed across a screen for 2.5 seconds. (Incongruent sentences were made by taking a sensible sentence, and switching out the last word for something that worked grammatically but was otherwise nonsense, like “This morning I ate a bowl of shoes” versus the “congruent” “This morning I ate a bowl of cereal.”) When asked to do this while also ignoring distractors — like other sentences on the screen — the heavier multitaskers did worse than their less multi-tasky peers. They were less able to enforce boundaries, as it were, and even more intriguingly, heavier multitaskers had greater activity in the prefrontal area of their brain, which is associated with self control — suggesting they had to exert more attentional effort in order to focus in the first place.

Of course, it’s very hard to say whether multitasking made these people’s brains work differently. It might be that people who are more impulsive tend to multitask more, a finding that’s come up in research. Or it might be that constant multitasking is changing the brain. Or it might be a blend of the two. “We know zero about what’s cause and effect,” Wagner says.

To, Jason Chein, the head of Temple University’s Neurocognition Lab, one of the strongest findings in the literature thus far is in how devices manipulate our memory, even beyond the distraction we usually assume with multitasking. Steve Jobs liked to say that a computer would be like a “bicycle for the mind,” but it turns out, in many cases, it’s more like a drone: rather than amplifying the way we think, it does the thinking for us. And this is a problem if you’re trying to get better at some cognitive skill. This can be seen in GPS: when you’re using Google Maps to guide you around places, you build a worse mental map than if you were navigating by landmarks. In a 2013 paper, people who walked around a museum with a camera taking pictures of art had worse recall of details of the objects and their locations than people who observed them device free. Similarly, a 2011 paper with the ominous title “Google Effects on Memory: Cognitive Consequences of Having Information at Our Fingertips” found that when people are asked difficult questions, they’re more likely to think about how they could access it than recall the information itself. “The internet has become a primary form of external or transactive memory, where information is stored collectively outside ourselves,” the authors wrote.

The way to remember something is to show your brain that it’s important, and that’s done by mentally engaging with material, whether it’s a new neighborhood, information for a test or a presentation, or the names of your new colleagues. Attention is the initial phase of memory, so things like GPS that relieve you of needing to attend to information also remove your opportunity to remember.

That’s why, Chein says, it’s important to be aware of what cognitive processes you’re outsourcing and what you’re keeping in house. If you’re traveling somewhere you’ll never return to, just GPS it. “But if you just moved into a new neighborhood, and you’re thinking, ‘I would really like to learn the lay of the land here,’ it might be effective to not GPS, ” he says.

When you’re studying multitasking, then, what you’re really studying is attention, and how our habits of attention affect our memory and brains more generally. Wagner, the Stanford psychologist, says that the literature on multitasking needs to be “glued into” the literature on meditation — since if multitasking is training you to try to pay attention to a bunch of things at once, mindfulness is consciously attending to a single object, and when your attention inevitably wanders away from the sensations of your breath, returning it there. While the research on this overlap is small, it is promising: a small 2016 study of light and heavy multitaskers found that the heavier got a bigger boost from a short-term mindfulness intervention, suggesting that meditation could provide a counterweight to the multitasking that pervades our lives. Your brain is getting habituated all the time either way: the question is whether it’s thousands of Silicon Valley engineers training your brain, or you.