During the course of the last month, there have been a couple of interesting developments in the – admittedly niche – field of what-technology-is-doing-to-our-teenagers’-brains. Both were widely reported in the media and were for the most part a refreshing change from the hyperbole and sensationalism that often surrounds this area.
First, Imperial College announced a new study investigating whether the radiofrequency waves emitted by mobile phones affect the cognitive abilities of adolescents. In the Study of Cognition, Adolescents and Mobile Phones, or SCAMP, 2500 year 7 students will be asked about how they use mobile phones and other wireless technologies, and will complete tasks measuring cognitive abilities like memory, reaction times and language comprehension. Two years later, the students will complete these questionnaires and tasks again, allowing the researchers to track changing use of mobile phones and see whether this is associated with changes in cognitive abilities.
The impetus behind this kind of study is the worry that radiofrequency waves have some biological effect on the brain, which translates into impaired functioning. However, research has so far produced equivocal results. These studies usually involve participants wearing a makeshift hat with a mobile phone attached, which is either turned off or on. While wearing this hat, participants complete a battery of cognitive tasks. Some studies have found that participants improve on measures like reaction times or attention when the phone is on, while others have found that participants get worse, or that there is simply no effect at all.
One way to make sense of confusing data like this is to perform a meta-analysis, which combines the results for several studies. In 2007, one such paper found that overall, when the mobile phone was turned on, participants were faster at mental arithmetic but slower at recalling information. But these effects were so small that they were essentially irrelevant in real-world scenarios and could possibly be attributed to methodological issues in some of the studies. So there seems to be scant evidence for radiofrequency waves causing any kind of cognitive changes.
This of course doesn’t rule out the possibility that long-term exposure to radiofrequency waves could have a cumulative effect which is not apparent in these one-off experimental manipulations. This could be of special concern in children and adolescents, whose brains are still developing and who might therefore be more sensitive to the biological effects of absorbing radiofrequency radiation. But do the radiofrequency waves emitted by mobile phones actually have any physiological effects in the brain?
The short answer is ‘probably not’. Like all electromagnetic radiation, radiofrequency waves carry energy which is absorbed by nearby body tissues. This energy causes the molecules in the tissue to vibrate, and at high enough levels this will cause heating – this is more-or-less how your microwave works. However, the mobile phone industry restricts the amount of energy that is absorbed in the head and brain by placing limits on the output power of the phone. (If you are interested, in the UK the maximum amount of energy allowed to be absorbed is 2 watts per kilogram of tissue, averaged over a 6 minute period). A report by the Health Protection Agency concluded that there was no clear evidence that radiofrequency waves have any biological effect at the power levels typical of mobile phones.
Of course history is replete with examples of things which have turned out to be harmful to us, despite their widespread use. The Health Protection Agency also acknowledges that mobile devices are relatively new technologies and research is still in its infancy. The news of Imperial’s latest study is therefore welcome, as it will bring us much-needed data. It is all too easy to whip up a panic over technology with little recourse to actual research. Which brings me to the second development of the month…
Shortly after Imperial’s announcement, a paper was released by Kathryn Mills in Sarah-Jayne Blakemore’s group at UCL, challenging the notion that internet use is negatively affecting adolescents’ brains. These sorts of claims are probably familiar to us all – it seems like a week doesn’t go by without reports that the internet is “rewiring” our brains, causing widespread addiction or making us socially inept.
But Mills’ paper argues that these claims are wildly exaggerated. Reviewing 134 studies on the effect of the internet on adolescent brains, Mills concludes that there is very little evidence that normal internet use is negatively affecting the cognitive abilities of young people. Teenagers are not using the internet at the expense of other, health-related activities, and in fact rather than producing socially incompetent youth, communication on the internet may increase social cohesion. And while – like any technology – the internet is likely to influence the strategies we choose to process information, that doesn’t mean that it is causing detrimental, long-term neural changes.
I’d strongly recommend reading the original paper or Mills’ article on boingboing for further details. But perhaps the most important message in the paper is that we cannot go beyond the available evidence to draw our own conclusions about how technology affects the brain and cognition. The lack of evidence does not necessarily mean that we won’t find some damaging effect of internet use in the future, but we can only be sure one way or the other by actually researching the area.
So it was a shame that in reporting the publication of this paper, the media felt the need to get a quote from Susan Greenfield, an Oxford-based professor who has repeatedly claimed that the internet and other technologies are fundamentally changing our brains for the worse. Greenfield has been strongly criticised by high profile scientists for talking far beyond the evidence and never publishing her theories so that they can be peer reviewed – yet she is still given a platform in the media. I had the dubious privilege of attending a talk by Greenfield recently, in which she casually dismissed Mills’ paper – which she hadn’t read – and equated the supposed neurocognitive changes resulting from internet use with climate change. This kind of sensationalist talk is the antithesis of the measured, scientific approach that this area needs.
I am happy, then, that there have been two interesting and highly publicised developments in the past month which have taken just this approach when it comes to studying the effects of technology on the brain. Whether we are interested in the effects of radiofrequency waves on our ability to quickly react to information or in the consequences of internet use on social cognition, we need proper, peer-reviewed research to inform our understanding.
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