In the study involving spyware, for example, two professors of business administration at the University of Vermont found that “students engage in substantial multitasking behavior with their laptops and have non-course-related software applications open and active about 42 percent of the time.” The professors, James Kraushaar and David Novak, obtained students’ permission before installing the monitoring software on their computers—so, as in Rosen’s study, the students were engaging in flagrant multitasking even though they knew their actions were being recorded.
Another study, carried out at St. John’s University in New York, used human observers stationed at the back of the classroom to record the technological activities of law students. The spies reported that 58 percent of second- and third-year law students who had laptops in class were using them for “non-class purposes” more than half the time. (First-year students were far more likely to use their computers for taking notes, although an observer did note one first-year student texting just 17 minutes into her very first class—the beginning of her law school career.)
Texting, emailing, and posting on Facebook and other social media sites are by far the most common digital activities students undertake while learning, according to Rosen. That’s a problem, because these operations are actually quite mentally complex, and they draw on the same mental resources—using language, parsing meaning—demanded by schoolwork.
David Meyer, a psychology professor at the University of Michigan who’s studied the effects of divided attention on learning, takes a firm line on the brain’s ability to multitask: “Under most conditions, the brain simply cannot do two complex tasks at the same time. It can happen only when the two tasks are both very simple and when they don’t compete with each other for the same mental resources. An example would be folding laundry and listening to the weather report on the radio. That’s fine. But listening to a lecture while texting, or doing homework and being on Facebook—each of these tasks is very demanding, and each of them uses the same area of the brain, the prefrontal cortex.”
Young people think they can perform two challenging tasks at once, Meyer acknowledges, but “they are deluded,” he declares. It’s difficult for anyone to properly evaluate how well his or her own mental processes are operating, he points out, because most of these processes are unconscious. And, Meyer adds, “there’s nothing magical about the brains of so-called ‘digital natives’ that keeps them from suffering the inefficiencies of multitasking. They may like to do it, they may even be addicted to it, but there’s no getting around the fact that it’s far better to focus on one task from start to finish.”
Researchers have documented a cascade of negative outcomes that occurs when students multitask while doing schoolwork. First, the assignment takes longer to complete, because of the time spent on distracting activities and because, upon returning to the assignment, the student has to refamiliarize himself with the material.
Second, the mental fatigue caused by repeatedly dropping and picking up a mental thread leads to more mistakes. The cognitive cost of such task-switching is especially high when students alternate between tasks that call for different sets of expressive “rules”—the formal, precise language required for an English essay, for example, and the casual, friendly tone of an email to a friend.
Third, students’ subsequent memory of what they’re working on will be impaired if their attention is divided. Although we often assume that our memories fail at the moment we can’t recall a fact or concept, the failure may actually have occurred earlier, at the time we originally saved, or encoded, the memory. The moment of encoding is what matters most for retention, and dozens of laboratory studies have demonstrated that when our attention is divided during encoding, we remember that piece of information less well—or not at all. As the unlucky student spotlighted by Rosen can attest, we can’t remember something that never really entered our consciousness in the first place. And a study last month showed that students who multitask on laptops in class distract not just themselves but also their peers who see what they’re doing.
Fourth, some research has suggested that when we’re distracted, our brains actually process and store information in different, less useful ways. In a 2006 study in the Proceedings of the National Academy of Sciences, Russell Poldrack of the University of Texas–Austin and two colleagues asked participants to engage in a learning activity on a computer while also carrying out a second task, counting musical tones that sounded while they worked. Study subjects who did both tasks at once appeared to learn just as well as subjects who did the first task by itself. But upon further probing, the former group proved much less adept at extending and extrapolating their new knowledge to novel contexts—a key capacity that psychologists call transfer.
Brain scans taken during Poldrack’s experiment revealed that different regions of the brain were active under the two conditions, indicating that the brain engages in a different form of memory when forced to pay attention to two streams of information at once. The results suggest, the scientists wrote, that “even if distraction does not decrease the overall level of learning, it can result in the acquisition of knowledge that can be applied less flexibly in new situations.”
Finally, researchers are beginning to demonstrate that media multitasking while learning is negatively associated with students’ grades. In Rosen’s study, students who used Facebook during the 15-minute observation period had lower grade-point averages than those who didn’t go on the site. And two recent studies by Reynol Junco, a faculty associate at Harvard’s Berkman Center for Internet & Society, found that texting and using Facebook—in class and while doing homework—were negatively correlated with college students’ GPAs. “Engaging in Facebook use or texting while trying to complete schoolwork may tax students’ capacity for cognitive processing and preclude deeper learning,” write Junco and a co-author. (Of course, it’s also plausible that the texting and Facebooking students are those with less willpower or motivation, and thus likely to have lower GPAs even aside from their use of technology.)