On manipulating memories, we're not as far behind Hollywood as you might think

Deep brain stimulation is racing ahead, and the ethical issues associated with it are starting to be debated.

Remember Total Recall? When the film came out in 1990, its premise, in which people take virtual holidays using memory manipulation, seemed farfetched. But on 20 August President Obama’s commission on bioethics debated what we ought to do about memory manipulation. That’s because it is just one of many invasive actions we are beginning to perform on the brain.
 
This month, the first trials of a new technique for controlling Parkinson’s disease began. A German sufferer has had a “deep brain stimulation” device, essentially a pair of electrodes, implanted in his brain. It will monitor the brain’s activity to deliver electrical currents designed to combat tremors and muscle rigidity. A similar technique has been shown, in a few cases, to reverse the shrinkage of brain tissues associated with Alzheimer’s disease. This reversal was not only about the neural tissue’s physical appearance: it led to improved brain functioning. No one knows how it works; the best guess is that it stimulates the growth of neurons.
 
Deep brain stimulation is also a treatment option if you have obsessive compulsive disorder. OCD appears to arise when electrical circuits conveying signals between the emotional and the decision-making parts of the brain become stuck in feedback loops. That leads to people compulsively repeating actions because the anxieties associated with not having done the task don’t get erased. A jolt of electricity seems to clear the brain jam, however. Similar treatments seem to be a cure for depression in some people.
 
And, true to Hollywood, we are now manipulating memories. We’re not yet at the virtual holiday stage, but mice are starting to have some strange experiences. Last month it was reported that electricity delivered to a mouse’s hippocampus gave it a memory of receiving a shock to the foot.
 
Hence the need for ethical review: it is easy to see how this could eventually be used to create a tool for controlling errant prisoners, say, or mental-health patients. Perhaps you remember the electroconvulsive “therapy” punishment in One Flew Over the Cuckoo’s Nest? It’s still seen as a treatment option for depression but some think it’s too blunt an instrument. Deep brain stimulation is far less blunt – yet who decides just how blunt is acceptable?
 
There are many other issues to face. As we begin our assault on the brain, we will begin to gather information that might turn out to be problematic. Brain experiments are already suggesting that some people have naturally poor control over impulsive actions, and are more prone to criminal or antisocial behaviour. It is important that such information should not get thrown casually into the public sphere.
 
For all the appropriate caution, let’s acknowledge that some of the things we’re learning to do to the brain are really rather exciting. Having a virtual holiday might sound like a bore, but what about having razor-sharp focus at the flick of a switch? The US military is piloting a scheme that is mind-bendingly futuristic: a DC electrical current applied to the brain that in effect puts you into a high-concentration zone. With “transcranial direct current stimulation”, learning is accelerated and performance in tasks that require mental focus is significantly enhanced.
 
The Americans are using it to improve sniper training but that won’t be the only application. One day soon you might unplug yourself and utter the immortal words: “I know kung fu.” Hollywood races ahead, but we’re not as far behind as you might think.
Jack Nicholson in the film version of "One Flew Over the Cuckoo's Nest".

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 26 August 2013 issue of the New Statesman, How the dream died

Davide Restivo at Wikimedia Commons
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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.