An excerpt from Nicholas Carr’s book, The Shallows: What the Internet is Doing to our Brains (W. W. Norton, June 2010) appeared in Wired (June 2010, pp. 112-118). Here is an excerpt from that excerpt—which though brief, strikes me as rather compelling evidence that The Shallows falls into the Must Reading category. Even for those whose time is already fully consumed with busyness, activities, commuting, the media, work, and need I mention, the online world of the Internet.
The mental consequences of our online info-crunching are not universally bad. Certain cognitive skills are strengthened by our use of computers and the Net. These tend to involve more primitive mental functions, such as hand-eye coordination, reflex response, and the processing of visual cues. One much-cited study of videogaming, published in Nature in 2003, revealed that after just 10 days of playing action games on computers, a group of young people had significantly boosted the speed with which they could shift their visual focus between various images and tasks.
It’s likely that Web browsing also strengthens brain functions related to fast paced problem-solving, particularly when it requires spotting patterns in a welter of data. A British study of the way women search for medical information online indicated that an experienced Internet user can, at least in some cases, assess the trustworthiness and probable value of a Web page in a matter of seconds. The more we practice surfing and scanning, the more adept our brain becomes at those tasks. (Other academics, like Clay Shirky, maintain that the Web provides us with a valuable outlet for a growing “cognitive surplus.”)
But it would be a serious mistake to look narrowly at such benefits and conclude that the Web is making us smarter. In a Science article published in early 2009, prominent developmental psychologist Patricia Greenfield reviewed more than 40 studies of the effects of various types of media on intelligence and learning ability. She concluded that “every medium develops some cognitive skills at the expense of others.” Our growing use of the Net and other screen based technologies, she wrote, has led to the “widespread and sophisticated development of visual-spatial skills.” But those gains go hand in hand with a weakening of our capacity for the kind of “deep processing” that underpins “mindful knowledge acquisition, inductive analysis, critical thinking, imagination, and reflection.”
We know that the human brain is highly plastic; neurons and synapses change as circumstances change. When we adapt to a new cultural phenomenon, including the use of a new medium, we end up with a different brain, says Michael Merzenich, a pioneer of the field of neuroplasticity. That means our online habits continue to reverberate in the workings of our brain cells even when we’re not at a computer. We’re exercising the neural circuits devoted to skimming and multitasking while ignoring those used for reading and thinking deeply.
Last year, researchers at Stanford found signs that this shift may already be well under way. They gave a battery of cognitive tests to a group of heavy media multitaskers as well as a group of relatively light ones. They discovered that the heavy multitaskers were much more easily distracted, had significantly less control over their working memory, and were generally much less able to concentrate on a task. Intensive multitaskers are “suckers for irrelevancy,” says Clifford Nass, one professor who did the research. “Everything distracts them." Merzenich offers an even bleaker assessment: As we multitask online, we are “training our brains to pay attention to the crap.”