More evidence of Net’s effect on the brain

A new study provides evidence that heavy internet use by the young results in “brain structural alterations” of a kind associated with “impairment of cognitive control.” The study, published this month in PLoS ONE, was conducted in China, where approximately 14 percent of urban youths – some 24 million kids – are believed to suffer from so-called “internet addiction disorder.” Using brain scans, the researchers compared the brains of 18 adolescents who spend around eight to twelve hours a day online (playing games, mainly) with the brains of 18 adolescents who spend less than 2 hours a day online. The heavy Net users exhibited gray-matter “atrophy” as well as other “abnormalities,” and the changes appeared to grow more severe the longer the kids engaged in intensive Net use.

The whole subject of Internet addiction remains controversial among experts, but, according to a Scientific American article on the new research, the study “cuts through much of the debate and hints that excessive time online can physically rewire a brain.” The Scientific American piece translates the key findings into layman’s terms:

One set of [MRI] images focused on gray matter at the brain’s wrinkled surface, or cortex, where processing of speech, memory, motor control, emotion, sensory and other information occurs … The researchers discovered several small regions in online addicts’ brains shrunk, in some cases as much as 10 to 20 percent. The affected regions included the dorsolateral prefrontal cortex, rostral anterior cingulate cortex, supplementary motor area and parts of the cerebellum.

What’s more, the longer the addiction’s duration, the more pronounced the tissue reduction. The study’s authors suggest this shrinkage could lead to negative effects, such as reduced inhibition of inappropriate behavior and diminished goal orientation …

As another crucial part of the new study on Internet addiction, the research team zeroed in on tissue deep in the brain called white matter, which links together its various regions. The scans showed increased white matter density in the right parahippocampal gyrus, a spot also tied to memory formation and retrieval. In another spot called the left posterior limb of the internal capsule, which is linked to cognitive and executive functions, white matter density dropped relative to the rest of the brain. [The researchers suggest that the white matter changes] may make it harder for Internet addicts to temporarily store and retrieve information … [and] could impair decision-making abilities—including those to trump the desire to stay online and return to the real world.

University College London neuroscientist Karl Friston tells Scientific American that while the shrinkage in gray matter is “quite extreme,” it’s “not surprising” when you take into account the plasticity of the adolescent brain: “Our brains grow wildly until our early teens, then we start pruning and toning areas to work more efficiently. So these areas may just be relevant to being a good online gamer, and were optimized for that.” But the study was a rigorous one, and the fact “that the results show anything significant at all is very telling,” Friston says. Further research will be required to confirm the study’s findings and to shed further light on behavioral and cognitive consequences of the changes.

7 thoughts on “More evidence of Net’s effect on the brain

  1. Margaretweigel

    Interesting study. I’d ask if these changes were seen as permanent/irreversible, and more broadly speaking whether these changes are seen as negative or positive… clearly they’re presented here in a negative light but perhaps we’re looking at some evolution-type changes (cue Kevin Kelly…)

  2. Kevin Kelly

    No doubt. What I would like to know (from further studies) is how internet addiction differs from TV addition, or even reading addiction. Let’s assume the young will become “addicted” to something. What is the best thing for you to get addicted to? (Have not read the paper yet.)

  3. Nick Carr

    The “addiction” question is less interesting to me than the documentation of brain changes from the use of the technology and the implications of those changes for thinking.

    As for the “best thing” to be addicted to, I would say that it’s nothing. Compulsive consumption of anything erodes the self.

    (And the brain changes documented in this study don’t seem to be evolutionary, ie, genetic, but rather plastic adaptations of the brain in response to behavior.)

  4. an691

    Seems to me that more or as much than the web or the net in itself, this alteration is due to the associated content (or lack thereof) and to a certain mindset which is particularly present on the web and IT in general, that could be characterized as a mix of blind faith in progress and having forgotten what a written thing is, independently of the medium. A discussion about this below :

  5. an691

    And wouldn’t be surprised about this study being crap, by the way, as is AI, singularity theory Messiah waiting, and all this junk.

    (different in this case, but still)

  6. Nick Carr


    Thanks for the comments.

    The study doesn’t appear to be “crap,” at least not to this confessedly lay reader, but that doesn’t mean it won’t be contradicted by future research. It’s one piece of evidence from one study that has both strengths and limitations.


  7. an691

    Yes maybe Nick, but the real problem with IT (people doing it) is that it is still totally shywing away from its huge need of identifiers, thinking it could be different from other domains, or thinking it could work like words or natural language, which of course is totally stupid.

    Meanwhile the huge complexity of current systems and difficulty to have them evolve, is primarily due to not recognizing that.

    As to social networks and the like, having them move towards huge monopols in a non anonymous or non pseudonyms mindset (at least for facebook) is far from being a fatality.

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