In an article in Science, Patricia Greenfield, a developmental psychologist who runs UCLA’s Children’s Digital Media Center, reviewed dozens of studies on how different media technologies influence our cognitive abilities. Some of the studies indicated that certain computer tasks, like playing video games, increase the speed at which people can shift their focus among icons and other images on screens. Other studies, however, found that such rapid shifts in focus, even if performed adeptly, result in less rigorous and ‘more automatic’ thinking.
In one experiment at an American university, half a class of students was allowed to use internet-connected laptops during a lecture, while the other half had to keep their computers shut. Those who browsed the web performed much worse on a subsequent test of how well they retained the lecture’s content. Earlier experiments revealed that as the number of links in an online document goes up, reading comprehension falls, and as more types of information are placed on a screen, we remember less of what we see.
Greenfield concluded that ‘every medium develops some cognitive skills at the expense of others’. Our growing use of screen-based media, she said, has strengthened visual-spatial intelligence, which can strengthen the ability to do jobs that involve keeping track of lots of rapidly changing signals, like piloting a plane or monitoring a patient during surgery. However, that has been accompanied by ‘new weaknesses in higher-order cognitive processes’, including ‘abstract vocabulary, mindfulness, reflection, inductive problem-solving, critical thinking and imagination’. We’re becoming, in a word, shallower.
Studies of our behaviour online support this conclusion. German researchers found that web browsers usually spend less than ten seconds looking at a page. Even people doing academic research online tend to ‘bounce’ rapidly between documents, rarely reading more than a page or two, according to a University College London study. Such mental juggling takes a big toll. In a recent experiment at Stanford University, researchers gave various cognitive tests to 49 people who do a lot of media multitasking and 52 people who multitask much less frequently. The heavy multitaskers performed poorly on all the tests. They were more easily distracted, had less control over their attention, and were much less able to distinguish important information from trivia. The researchers were surprised by the results. They expected the intensive multitaskers to have gained some mental advantages. That wasn’t the case, though. In fact, the multitaskers weren’t even good at multitasking. ‘Everything distracts them,’ said Clifford Nass, one of the researchers.
It would be one thing if the ill effects went away as soon as we turned off our computers and mobiles, but they don’t. The cellular structure of the human brain, scientists have discovered, adapts readily to the tools we use to find, store and share information. By changing our habits of mind, each new technology strengthens certain neural pathways and weakens others. The alterations shape the way we think even when we’re not using the technology. The pioneering neuroscientist Michael Merzenich believes our brains are being ‘massively remodelled’ by our ever-intensifying use of the web and related media. In 2009, he said that he was profoundly worried about the cognitive consequences of the constant distractions and interruptions the internet bombards us with. The long-term effect on the quality of our intellectual lives, he said, could be ‘deadly’.
Not all distractions are bad. As most of us know, if we concentrate too intensively on a tough problem, we can get stuck in a mental rut. However, if we let the problem sit unattended for a time, we often return to it with a fresh perspective and a burst of creativity. Research by Dutch psychologist Ap Dijksterhuis indicates that such breaks in our attention give our unconscious mind time to grapple with a problem, bringing to bear information and cognitive processes unavailable to conscious deliberation. We usually make better decisions, his experiments reveal, if we shift our attention away from a mental challenge for a time.
But Dijksterhuis’s work also shows that our unconscious thought processes don’t engage with a problem until we’ve clearly and consciously defined what the problem is. If we don’t have a particular goal in mind, he writes, ‘unconscious thought does not occur’. The constant distractedness that the Net encourages is very different from the kind of temporary, purposeful diversion of our mind that refreshes our thinking. What we seem to be sacrificing in our surfing and searching is our capacity to engage in the quieter, attentive modes of thought that underpin contemplation, reflection and introspection.