Against Neuroethics

The BPS has published a discussion paper on “Neuroethics”. Neuroethics is an unnecessary phrase which covers a hodge-podge of ethical concerns for psychology researchers and broader societal concerns over the application of findings from the cognitive neurosciences.

The paper, prepared by the impressive team of Carl Senior, Patrick Haggard and John Oates, is mostly a discussion of the particular ethical issues that might arise from research using cognitive neuroscience techniques such as fMRI. Overall, it seems to me that all of the substantive ethical issues mentioned by the paper are treated at length by existing moral philosophy (and in particular by medical ethics). It is not clear that psychology and neurosciences have anything to add, which should be a first clue that the idea of “neuroethics” is inherently dubious.

A particularly revealing moment is the authors’ discussion of the evidence showing that people are more likely to believe an explanation when it is presented alongside a picture of a brain scan (McCabe & Castel, 2008 – covered on Mind Hacks here). This, for the authors of the discussion paper, raises the spectre of BPS members having “undue influence” by accompanying their explanations with pictures of brain scans.

In light of the persuasive power of brain scan imagery its use to illustrate any fact should be restricted as much as possible. Brain scan imagery should not be included on recruitment posters for participation in experiments

Here, the authors seem to have been affected by a peculiar version of the very effect they are warning against! They treat influence due to brain imagery as somehow exceptional, in the same way that people in the experiments treat explanations using brain imagery as somehow exceptional. Consider how the argument would look if it was a prescription against accompanying your communications with partcular phrases, or with offers of financial rewards. The way explanations are phrased affects how often they are believed – that does not mean psychologists should not try to be persuasive, nor that they are wrangling the minds of the public in an exceptional way if they are. There is evidence that monetary rewards, like brain imagery, can distort people’s judgement (see, e.g., Hsee, Zhang & Zhang, 2003) – the BPS has not recommended that members can’t pay people to participate in experiments.

It is part of normal cognitive function to be affected by the environment, and there are many quirks about the way we humans are affected by the exact content and structure of the environment. Examples of that influence are not automatically examples of “undue influence”, regardless of whether they involve brain imagery or not.

There are genuine ethical issues which are peculiar to cognitive neuroscience, but our duty to attend to these is better served by seeing brain related issues in the context of general ethics, rather than pandering to the kind of exceptionalism that the phrase “neuroethics” encourages.

A discussion paper: neuroethics and the british psychological society research ethics code

Hsee, C. K., Yu, F., Zhang, J., & Zhang, Y. (2003). Medium maximization. Journal of Consumer Research, 1–14.

McCabe, D. P., & Castel, A. D. (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning. Cognition, 107(1), 343-352. doi:16/j.cognition.2007.07.017

Doubts about social contagion

Slate has an important article about how the studies behind last year’s headlines saying that things like divorce, obesity and loneliness spread through social networks like a ‘contagion’ may not be as sound as the stories suggested.

The headline grabbing study on ‘divorce contagion’ has still yet to be published as it hasn’t made it through the scientific peer-review process. The authors are criticised for talking to the media about the conclusions before the results have been confirmed.

Other studies were published in leading journals but the same publications have been much less keen to air criticisms of the work despite the fact that many leading names in the network analysis community have highlighted problems in the methods used in the research.

This is perhaps the real story here, as many conclusions turn out to be wrong in science, but the big name journals work much more like the popular media than they like to admit – heralding flashy new findings but being unwilling to take on the responsibility of continuing the debate after the glitz has faded.

It’s worth noting that the debate about the ‘social contagion’ studies is ongoing but the Slate article has some good coverage of where the growing doubts lie.

Link to Slate article ‘Disconnected?’

Cross Road Blues

The July issue of the British Journal of Psychiatry has another edition of its ‘psychiatry in 100 words’ series – this time on melancholia and the blues legend Robert Johnson.

‘I got stones in my pathway/And my road seems dark at night/I have pains in my heart/They have taken my appetite’. Robert Johnson, known as the King of the Delta blues singers, distilled into these lines the essence of severe depressive illness – somatic ills, fear and suspicion, emotional and physical pain, nocturnal troubles and struggle against obstacles. The words are one with the powerful, haunting music. ICD-10 and DSM-IV have their place, but poets have often been there before us, and done a better job. We can all learn from Robert Johnson, born just 100 years ago.


Link to BJP ‘Melancholia in 100 words’.

Naomi Wolf, porn and the misuse of dopamine

‘Is pornography driving men crazy?’ asks campaigner Naomi Wolf in a CNN article that contains a spectacular misunderstanding of neuroscience applied to a shaky moral conclusion.

Wolf asks suggests that the widespread availability and consumption of pornography is “rewiring the male brain” and “causing them to have more difficulty controlling their impulses”.

According to her article, pornography causes “rapid densensitization” to sexual stimulation which is “desensitizing healthy young men to the erotic appeal of their own partners” and means “ordinary sexual images eventually lose their power, leading consumers to need images that break other taboos in other kinds of ways, in order to feel as good.”

Moreover, she says “some men (and women) have a “dopamine hole” – their brains’ reward systems are less efficient – making them more likely to become addicted to more extreme porn more easily.”

Wolf cites the function of dopamine to back up her argument and says this provides “an increasing body of scientific evidence” to support her ideas.

It does not, and unfortunately, Wolf clearly does not understand either the function or the relevance of the dopamine system to this process, but we’ll get onto that in the moment.

Purely on the premise of the article, I was troubled by the fact that “breaking taboos” is considered to be a form of pathology and it lumps any sort of progression in sexual interest as a move toward the “extreme”.

‘Taboo’ and ‘extreme’ are really not the issue here as both are a matter of perception and taste. What is important is ‘consensual’ and ‘non-consensual’ and when the evidence is examined as a whole there is no conclusive evidence that pornography increases sexual violence or the approval of it (cross-sectional studies tend to find a link, experimental and crime data studies do not).

To the contrary, wanting new and different sexual experiences is for the majority a healthy form of sexual exploration, whether that be through porn or other forms of sexual behaviour.

One part of the motivation for this is probably that people do indeed become densensitised to specific sexual images or activities, so seeing the same thing or doing the same thing over and over is likely to lead to boredom – as any women’s magazine will make abundantly clear on their advice pages.

But this is no different to densensitisation to any form of emotional experience. I contacted Jim Pfaus, the researcher mentioned in the article, who has conducted several unpublished studies showing that physiological arousal reduces on repeat viewing of sexual images, but he agrees that this is in line with standard habituation of arousal to most type of emotional images, not just sexual, that happens equally with men and with women.

It’s important to point out that this densensitisation research is almost always on the repetition of exactly the same images. We would clearly be in trouble if any sexual experience caused us to densensitise to sex as we’d likely lose all interest by our early twenties.

However, it is Wolf’s description of the dopamine system where things get really weird:

Since then, a great deal of data on the brain’s reward system has accumulated to explain this rewiring more concretely. We now know that porn delivers rewards to the male brain in the form of a short-term dopamine boost, which, for an hour or two afterwards, lifts men’s mood and makes them feel good in general. The neural circuitry is identical to that for other addictive triggers, such as gambling or cocaine.

The addictive potential is also identical: just as gamblers and cocaine users can become compulsive, needing to gamble or snort more and more to get the same dopamine boost, so can men consuming pornography become hooked. As with these other reward triggers, after the dopamine burst wears off, the consumer feels a letdown – irritable, anxious, and longing for the next fix.

Wolf is accidentally right when she says that porn ‘rewires the brain’ but as everything rewires the brain, this tells us nothing.

With regard to dopamine, it is indeed involved in sexual response, but this is not identical to the systems involved with gambling or cocaine as different rewards rely on different circuits in the brain – although doesn’t it sound great to lump those vices together?

Porn is portrayed as a dangerous addictive drug that hooks naive users and leads them into sexual depravity and dysfunction. The trouble is, if this is true (which by the way, it isn’t, research suggests both males and females find porn generally enhances their sex lives, it does not effect emotional closeness and it is not linked to risky sexual behaviours) it would also be true for sex itself which relies on, unsurprisingly, a remarkably similar dopamine reward system.

Furthermore, Wolf relies on a cartoon character version of the reward system where dopamine squirts are represented as the brain’s pleasurable pats on the back.

But the reward is not the dopamine. Dopamine is a neurochemical used for various types of signalling, none of which match the over-simplified version described in the article, that allow us to predict and detect rewards better in the future.

One of its most important functions is reward prediction where midbrain dopamine neurons fire when a big reward is expected even when it doesn’t occur – such as in a near-miss money-loss when gambling – a very unpleasant experience.

But what counts as a reward in Wolf’s dopamine system stereotype? Whatever makes the dopamine system fire. This is a hugely circular explanation and it doesn’t account for the huge variation in what we find rewarding and what turns us on.

This is especially important in sex because people are turned on by different things. Blondes, brunettes, men, women, transsexuals, feet, being spanked by women dressed as nuns (that list is just off the top of my head you understand).

Not all sex is rewarding to all people and people have their likes, dislikes and limits.

In other words, there is more to reward than the dopamine system and in many ways it is a slave to the rest of the brain which interprets and seeks out the things we most like. It is impossible to explain sexual motivation or sexual pathology purely or, indeed, mainly as a ‘dopamine problem’.

Wolf finishes by saying that “understanding how pornography affects the brain and wreaks havoc on male virility permits people to make better-informed choices” despite clearly not understanding how pornography could affect the brain and providing nothing but anecdotes about the effect on male sexual function.

This does not mean all porn is helpful or healthy, either to individuals or society, but we should be criticising it on established effects, not on misunderstood and poorly applied neuroscience deployed in the service of bolstering shaky conclusions about its personal impact.

Link to Naomi Wolf’s “Is pornography driving men crazy?”