The Shallows (16 page)

In 2005, Diana DeStefano and Jo-Anne LeFevre, psychologists with the Centre for Applied Cognitive Research at Canada’s Carleton University, undertook a comprehensive review of thirty-eight past experiments involving the reading of hypertext. Although not all the studies showed that hypertext diminished comprehension, they found “very little support” for the once-popular theory “that hypertext will lead to an enriched experience of the text.” To the contrary, the preponderance of evidence indicated that “the increased demands of decision-making and visual processing in hypertext impaired reading performance,” particularly when compared to “traditional linear presentation.” They concluded that “many features of hypertext resulted in increased cognitive load and thus may have required working memory capacity that exceeded readers’ capabilities.”
²⁴

THE WEB COMBINES
the technology of hypertext with the technology of multimedia to deliver what’s called “hypermedia.” It’s not just words that are served up and electronically linked, but also images, sounds, and moving pictures. Just as the pioneers of hypertext once believed that links would provide a richer learning experience for readers, many educators also assumed that multimedia, or “rich media,” as it’s sometimes called, would deepen comprehension and strengthen learning. The more inputs, the better. But this assumption, long accepted without much evidence, has also been contradicted by research. The division of attention demanded by multimedia further strains our cognitive abilities, diminishing our learning and weakening our understanding. When it comes to supplying the mind with the stuff of thought, more can be less.

In a study published in the journal
Media Psychology
in 2007, researchers recruited more than a hundred volunteers to watch a presentation about the country of Mali played through a Web browser on a computer. Some of the subjects watched a version of the presentation that included only a series of text pages. Another group watched a version that included, along with the pages of text, a window in which an audiovisual presentation of related material was streamed. The test subjects were able to stop and start the stream as they wished.

After viewing the presentation, the subjects took a ten-question quiz on the material. The text-only viewers answered an average of 7.04 of the questions correctly, while the multimedia viewers answered just 5.98 correctly—a significant difference, according to the researchers. The subjects were also asked a series of questions about their perceptions of the presentation. The text-only readers found it to be more interesting, more educational, more understandable, and more enjoyable than did the multimedia viewers, and the multimedia viewers were much more likely to agree with the statement “I did not learn anything from this presentation” than were the text-only readers. The multimedia technologies so common to the Web, the researchers concluded, “would seem to limit, rather than enhance, information acquisition.”
²⁵

In another experiment, a pair of Cornell researchers divided a class of students into two groups. One group was allowed to surf the Web while listening to a lecture. A log of their activity showed that they looked at sites related to the lecture’s content but also visited unrelated sites, checked their e-mail, went shopping, watched videos, and did all the other things that people do online. The second group heard the identical lecture but had to keep their laptops shut. Immediately afterward, both groups took a test measuring how well they could recall the information from the lecture. The surfers, the researchers report, “performed significantly poorer on immediate measures of memory for the to-be-learned content.” It didn’t matter, moreover, whether they surfed information related to the lecture or completely unrelated content—they all performed poorly. When the researchers repeated the experiment with another class, the results were the same.
²⁶

Kansas State University scholars conducted a similarly realistic study. They had a group of college students watch a typical CNN broadcast in which an anchor reported four news stories while various info-graphics flashed on the screen and a textual news crawl ran along the bottom. They had a second group watch the same programming but with the graphics and the news crawl stripped out. Subsequent tests found that the students who had watched the multimedia version remembered significantly fewer facts from the stories than those who had watched the simpler version. “It appears,” wrote the researchers, “that this multimessage format exceeded viewers’ attentional capacity.”
²⁷

Supplying information in more than one form doesn’t always take a toll on understanding. As we all know from reading illustrated textbooks and manuals, pictures can help clarify and reinforce written explanations. Education researchers have also found that carefully designed presentations that combine audio and visual explanations or instructions can enhance students’ learning. The reason, current theories suggest, is that our brains use different channels for processing what we see and what we hear. As Sweller explains, “Auditory and visual working memory are separate, at least to some extent, and because they are separate, effective working memory may be increased by using both processors rather than one.” As a result, in some cases “the negative effects of split attention might be ameliorated by using both auditory and visual modalities”—sounds and pictures, in other words.
²⁸
The Internet, however, wasn’t built by educators to optimize learning. It presents information not in a carefully balanced way but as a concentration-fragmenting mishmash.

The Net is, by design, an interruption system, a machine geared for dividing attention. That’s not only a result of its ability to display many different kinds of media simultaneously. It’s also a result of the ease with which it can be programmed to send and receive messages. Most e-mail applications, to take an obvious example, are set up to check automatically for new messages every five or ten minutes, and people routinely click the “check for new mail” button even more frequently than that. Studies of office workers who use computers reveal that they constantly stop what they’re doing to read and respond to incoming e-mails. It’s not unusual for them to glance at their in-box thirty or forty times an hour (though when asked how frequently they look, they’ll often give a much lower figure).
²⁹
Since each glance represents a small interruption of thought, a momentary redeployment of mental resources, the cognitive cost can be high. Psychological research long ago proved what most of us know from experience: frequent interruptions scatter our thoughts, weaken our memory, and make us tense and anxious. The more complex the train of thought we’re involved in, the greater the impairment the distractions cause.
³⁰

Beyond the influx of personal messages—not only e-mail but also instant messages and text messages—the Web increasingly supplies us with all manner of other automated notifications. Feed readers and news aggregators let us know whenever a new story appears at a favorite publication or blog. Social networks alert us to what our friends are doing, often moment by moment. Twitter and other microblogging services tell us whenever one of the people we “follow” broadcasts a new message. We can also set up alerts to monitor shifts in the value of our investments, news reports about particular people or events, updates to the software we use, new videos uploaded to YouTube, and so forth. Depending on how many information streams we subscribe to and the frequency with which they send out updates, we may field a dozen alerts an hour, and for the most connected among us, the number can be much higher. Each of them is a distraction, another intrusion on our thoughts, another bit of information that takes up precious space in our working memory.

Navigating the Web requires a particularly intensive form of mental multitasking. In addition to flooding our working memory with information, the juggling imposes what brain scientists call “switching costs” on our cognition. Every time we shift our attention, our brain has to reorient itself, further taxing our mental resources. As Maggie Jackson explains in
Distracted
, her book on multitasking, “the brain takes time to change goals, remember the rules needed for the new task, and block out cognitive interference from the previous, still-vivid activity.”
³¹
Many studies have shown that switching between just two tasks can add substantially to our cognitive load, impeding our thinking and increasing the likelihood that we’ll overlook or misinterpret important information. In one simple experiment, a group of adults was shown a series of colored shapes and asked to make predictions based on what they saw. They had to perform the task while wearing headphones that played a series of beeps. In one trial, they were told to ignore the beeps and just concentrate on the shapes. In a second trial, using a different set of visual cues, they were told to keep track of the number of beeps. After each go-through, they completed a test that required them to interpret what they had just done. In both trials, the subjects made predictions with equal success. But after the multitasking trial, they had a much harder time drawing conclusions about their experience. Switching between the two tasks short-circuited their understanding; they got the job done, but they lost its meaning. “Our results suggest that learning facts and concepts will be worse if you learn them while you’re distracted,” said the lead researcher, UCLA psychologist Russell Poldrack.
³²
On the Net, where we routinely juggle not just two but several mental tasks, the switching costs are all the higher.

It’s important to emphasize that the Net’s ability to monitor events and automatically send out messages and notifications is one of its great strengths as a communication technology. We rely on that capability to personalize the workings of the system, to program the vast database to respond to our particular needs, interests, and desires. We
want
to be interrupted, because each interruption brings us a valuable piece of information. To turn off these alerts is to risk feeling out of touch, or even socially isolated. The near-continuous stream of new information pumped out by the Web also plays to our natural tendency to “vastly overvalue what happens to us
right now
,” as Union College psychologist Christopher Chabris explains. We crave the new even when we know that “the new is more often trivial than essential.”
³³

And so we ask the Internet to keep interrupting us, in ever more and different ways. We willingly accept the loss of concentration and focus, the division of our attention and the fragmentation of our thoughts, in return for the wealth of compelling or at least diverting information we receive. Tuning out is not an option many of us would consider.

IN 1879, A
French ophthalmologist named Louis Émile Javal discovered that when people read, their eyes don’t sweep across the words in a perfectly fluid way. Their visual focus advances in little jumps, called saccades, pausing briefly at different points along each line. One of Javal’s colleagues at the University of Paris soon made another discovery: that the pattern of pauses, or “eye fixations,” can vary greatly depending on what’s being read and who’s doing the reading. In the wake of these discoveries, brain researchers began to use eye-tracking experiments to learn more about how we read and how our minds work. Such studies have also proven valuable in providing further insights into the Net’s effects on attention and cognition.

In 2006, Jakob Nielsen, a longtime consultant on the design of Web pages who has been studying online reading since the 1990s, conducted an eye-tracking study of Web users. He had 232 people wear a small camera that tracked their eye movements as they read pages of text and browsed other content. Nielsen found that hardly any of the participants read online text in a methodical, line-by-line way, as they’d typically read a page of text in a book. The vast majority skimmed the text quickly, their eyes skipping down the page in a pattern that resembled, roughly, the letter
F
. They’d start by glancing all the way across the first two or three lines of text. Then their eyes would drop down a bit, and they’d scan about halfway across a few more lines. Finally, they’d let their eyes cursorily drift a little farther down the left-hand side of the page. This pattern of online reading was confirmed by a subsequent eye-tracking study carried out at the Software Usability Research Laboratory at Wichita State University.
³⁴

“F,” wrote Nielsen, in summing up the findings for his clients, is “for
fast
. That’s how users read your precious content. In a few seconds, their eyes move at amazing speeds across your website’s words in a pattern that’s very different from what you learned in school.”
³⁵
As a complement to his eye-tracking study, Nielsen analyzed an extensive database on the behavior of Web users that had been compiled by a team of German researchers. They had monitored the computers of twenty-five people for an average of about a hundred days each, tracking the time the subjects spent looking at some fifty thousand Web pages. Parsing the data, Nielsen found that as the number of words on a page increases, the time a visitor spends looking at the page goes up, but only slightly. For every hundred additional words, the average viewer will spend just 4.4 more seconds perusing the page. Since even the most accomplished reader can read only about eighteen words in 4.4 seconds, Nielsen told his clients, “when you add verbiage to a page, you can assume that customers will read 18% of it.” And that, he cautioned, is almost certainly an overstatement. It’s unlikely that the people in the study were spending all their time reading; they were also probably glancing at pictures, videos, advertisements, and other types of content.
³⁶