Reading books does re-wire your brain, but so does everything else

Another day, another study misrepresented as causing our brains to change in some mysterious, irreversible way.

Is reading a book a way to get a short-term intelligence top-up? That’s the implication of a study by an Emory University team of neuroscientists, led by Gregory Berns. The Independent reported this as evidence that reading a novel can lead to a “boost” in brain function for “days” afterwards, while the LA Times says it means books “exercise muscles in the brain” so effectively that it can be detected for up to five days afterwards.

The study in question - “Short- and Long-Term Effects of a Novel on Connectivity in the Brain”, published in the journal Brain Connectivity in on 6 December (here’s the link) - isn’t quite as definitive as those headlines make out. It’s one of those instances where the media has fallen for the “[x] ‘rewires’ the brain” myth, one that’s as common (and as mistaken) as the “we only use ten percent of our brainpower” myth, or the “right brain/left brain” myth.

Everything we do makes our thinking organ ‘rewire’ itself, as it works by forming new connections between neurons, creating new neural networks - it’s called neuroplasticity. Those panic stories that appear in the Mail claiming that Facebook/porn/violent movies/etc. are causing long-term damage to the brains of our children are based on the dodgy assumption that those activities cause the brain to reconfigure itself in a harmful way, and for it to then get stuck like that, like pulling a face when the wind changes. Nope, that’s not how it works.

So, to the study. Here’s what it measured: 19 participants (not 21, as reported elsewhere) were scanned by an MRI machine over 19 days. There was a five day “wash-in” period to establish a baseline, nine days over which the participants read the novel, and a five day “wash-out” period to see how long changes were measured.

The book, in this experiment, was Pompeii by Robert Harris. “This novel was chosen because it was based on true events but written as historical fiction and conveyed in a classic narrative arc,” Berns writes. It’s a book that ends with a massive volcano blowing up and everybody dying, so the plot has a pretty predictable build-up and climax that would hopefully show up in the brain scans - and, what do you know, they did:

On the days after the reading, significant increases in connectivity were centered on hubs in the left angular/supramarginal gyri and right posterior temporal gyri. These hubs corresponded to regions previously associated with perspective taking and story comprehension, and the changes exhibited a timecourse that decayed rapidly after the completion of the novel.”

Translation: bits of the brain that do language stuff changed, and started changing back after the book ended. That might seem to justify the idea of books being used to “boost” brain function, but don't be too hasty.

Firstly, 19 participants is a tiny sample size, and secondly, there wasn’t a control group. Instead, “through repeated scans, each participant served as his or her own control to measure changes in resting-state connectivity after the consumption of the novel.” We can be relatively confident, because of this, that the changes in brain connectivity that were observed did happen - but we can’t be sure that it’s the books that caused it. The participants all went through similar experiences over 19 days, of which only a part was reading the same book.

Maybe the changes observed are what happens when you get used to sitting inside a big machine once a day for three weeks. Or, maybe it’s what happens when you take a quiz every day, something that Berns considers in his conclusion:

[Resting-state networks] are known to be altered by recent language comprehension tasks (Hasson et al., 2009) as well as visual categorization tasks (Stevens et al., 2010). Although the chapter readings were performed during the evenings before scans, the quizzes occurred just before the scan. The quizzes, therefore, might be responsible for such immediate changes in resting state, though the tasks differ in their orientation.”

Let’s accept that it is the book that did it - what does it tell us? That a book about a volcano exploding, with a simple plot, changed the structure of a small part of the brains of a small group of people. It’s a leap to then assume that it would lead to a boost in mental ability - either when it comes to the parts of the brain where changes were seen, or across the whole brain.

It also says nothing about what kinds of books cause the change. Is it all novels? Is non-fiction just as good? Is it a narrative that matters, or is experimental fiction just as useful? What about poetry, or fan fiction, or the comments section of YouTube? Or what about an article like the one you’re reading right now?

Scientific discovery tends to be a gradual thing, taking place over many years with many people building up a combined body of knowledge. This study is interesting in that context - not in any kind of way that can be used to attribute magical powers to novels. As much as we may love our favourite books, that's a bit of a stretch.

A scan of a human brain. (Image: Reigh LeBlanc/Flickr)

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.