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Porn and the plastic brain

28 Nov, 2011

In her shortlisted entry for the 2011 Wellcome Trust Science Writing PrizeCrystal Bennes looks at the malleable nature of our brain’s pleasure centres, focusing on pornography.

If you want to experience the power of neuroplastic change, I suggest you develop a porn habit.

Though still a relatively new theory on the neuroscience block, neuroplasticity – the notion that our adult brains can be cortically rewired through experience and environment – has begun to trickle down into public consciousness in the past few years thanks to accounts by people like psychiatrist Norman Doidge and neuroscientist V.S. Ramachandran.

Perhaps surprisingly, pornography provides a useful demonstration of the principles of neuroplasticity in practice. Pornography appears, at first glance, to be a purely instinctual matter. Not so, suggests Doidge in The Brain That Changes Itself, for if the buxom babes and well-endowed studs triggered responses that were supposedly the product of millions of years of evolution, we might assume that pornography would have remained unchanged over the years. As Doidge puts it, “we might expect the same triggers, body parts and proportions that appealed to the first consumers of porn would still excite us today”.

Anyone with an internet connection can see that this simply isn’t true. Pornography is a dynamic phenomenon that perfectly illustrates the progress of acquired tastes. Forty years ago “hardcore” porn typically meant the explicit depiction of sex between two or more partners, while “soft-core” porn tended to depict topless or nude women. Now, hardcore has evolved and its subsections have increased tenfold: BDSM, orgies, violence and humiliation, anal sex – you name it, pretty much anything goes. Today, soft-core porn resembles the hardcore images from only a few decades ago and half-naked images of women are unassailably commonplace, bombarding us from every mainstream media outlet conceivable.

This wider cultural trend hints at the more particular effects on the brain maps of individual consumers. As with other facets of human sexuality and romance, the key issue is tolerance. At a cultural and individual level we’re like drug addicts who can no longer get high on the images that once turned us on. And, as Marina Robinson observes in The Great Porn Experiment, the risk is that this tolerance can and will carry over into relationships, leading to potency problems and new, at times unwelcome, tastes.

Pornography is more exciting than satisfying because we have two separate pleasure systems in our brains: one that excites pleasure and one that satisfies pleasure. The exciting system relates to what’s referred to as the “appetitive pleasure”, or pleasure we get imagining things we desire – sex or good food. This chemistry is largely dopamine-related and raises our tension level. The second pleasure system has to do with satisfying this appetitive pleasure – when you actually get the sex or the food. Its neurochemistry is based on the release ofendorphins, which chill you out and contribute to a calming, fulfilling sense of pleasure.

It’s worth mentioning briefly that porn works not because the images excite us and cause us to think about sex, but because the images arouse us and cause our brains to think we’re actually having sex.

By offering your brain an endless stream of sexual objects for excitement, porn hyperactivates the appetitive system. Regular viewers develop new brain maps based on the photos they see and the videos they watch. According to neuroplasticity we have a “use it or lose it” brain, so when we develop a new map area we long to keep it activated. Just as our muscles become impatient for exercise if we’ve been sitting all day, so too do our senses hunger to be stimulated.

Activation of these brain reward systems is a normal, healthy component of human behavior – they direct us toward the things that keep us alive and promote our survival (food and water) or the survival of the species (sex). But as Robinson points out, the brains of porn users are “tricked into thinking that the consumption of so much porn is really valuable because it’s causing a mammoth release of exciting neurochemicals”. The brain has been rewired, however temporarily, to neglect formerly potent rewards (delicious food or sex) in favour of something else – in this case, porn.

But here’s the interesting twist. As an addictive substance, porn hijacks our dopamine system and gives us pleasure without our having to work for it. Some might say that’s not such a bad thing. But because porn meets all the conditions for neuroplastic change – repeated use, intense concentration and a reward system – regular users build up a tolerance, a tolerance that translates into changes in the brain.

Yet, unbelievably, we take the effects of this repetition for granted. Our activities significantly alter our brains and thus our brains have the ability to significantly alter our actions. We are creatures who absorb the environment around us, who suck up stimuli like a paper towel.

In a society that constantly likes to remind itself of its sexual liberation, where orgasms and masturbation are considered as important to physical health as exercise and eating well, porn is tolerated as an aide-de-amour-propre. The results of the great porn experiment remain to be seen but the shift in acquired sexual tastes at the cultural level, as indicated by porn consumption, is a fascinating indicator of plastic change in brains ever on the hunt for novelty.

Crystal Bennes

This is an edited version of Crystal’s original essay. Views expressed are the author’s own.

Find out more about the Wellcome Trust Science Writing Prize in association with the Guardian and the Observer and read our ‘How I write about science‘ series of tips for aspiring science writers.

Over the coming months, we’ll be publishing the shortlisted essays in this year’s inaugural competition.

Image Credit: All Glass Photo on Flickr
6 Comments leave one →
  1. 28 Nov, 2011 1:32 pm

    Hi I wanted to make a comment about using the work of Marnia Robinson – Marnia, not Marina – as I think it is quite controversial, and not in a good way.

    I first came across Marnia and her husband Gary’s work on The Good Men Project, an American-based website and blog for and about men.

    They have written a few articles at GMP all of them incredibly negative about pornography, and in particular heterosexual men’s use of porn. eg this article is called: ‘How porn can ruin your sex life and your marriage’

    http://goodmenproject.com/health/how-porn-can-ruin-your-sex-life-and-your-marriage/

    They claim to have a science background and to be using science to prove their points about the harmful nature of porn, but on looking at their website it is clear their ‘science’ is not exactly watertight, or even coming from a peer-reviewed environment. I might use the word ‘cranks’ to describe them.

    http://goodmenproject.com/author/marniarobinsongarywilson/

    I am not very impressed a piece has been shortlisted for the Wellcome prize that is based on such dodgy ‘science’ and does not include any critique of that science, and does not allude to the heated debate over pornography and its potential effects that is very well publicised and very politicised.

    Best wishes
    Quiet Riot Girl
    http://www.quietgirlriot.wordpress.com

  2. 28 Nov, 2011 6:59 pm

    Given research on porn is often limited by poorly designed studies that are under theorised and tend to privilege the use of undergraduate participants, it is important writing about this issue takes a critical and evidenced stance. I was disappointed this shortlisted piece for a science writing prize did not appear to fully engage with the wider evidence base nor political context of the influence of pornography.

    In an era where people’s pornography use often causes anxiety and where more research exploring issues around pornography is needed, discussions on the topic that oversimplify issues are not helpful. I found this piece lacked references to support key points made, oversimplified core terms such as ‘sex’ or ‘porn’, was ahistorical and seemed to be based on a theory that, while interesting, was not adequately interrogated.

    I will leave it to neuroscientists to address the claims made about the brain here, but I would draw attention to the following issues which I don’t think are fully explained:

    The term ‘pornography’ is used, but it isn’t really clear within this piece exactly what it means to the writer, nor is it made clear how the term has varying meanings to the public (and to those who oppose, support or are conflicted about porn).

    “Forty years ago “hardcore” porn typically meant the explicit depiction of sex between two or more partners, while “soft-core” porn tended to depict topless or nude women” – is this really the case? If so, is there a reference for it? Is the author talking about porn in the UK or other countries? Porn aimed at heterosexual audiences? While debates on hard vs soft core porn abound it would have been more interesting to see these terms picked apart and looked at in a critical way, not least in terms of how difficult it can be to operationalise such terms for research purposes.

    The claim that hardcore has ‘evolved’ also requires referencing, and perhaps reflecting on. Has ‘hard core’ (as defined by the author) evolved, or has our access to such imagery been made easier (meaning the many many genres of porn have always existed but our ability to see and share them has become far easier). That isn’t clear from this essay.

    The author states that hard core of yesteryear is now soft core porn, but again this could do with referencing and exploring. Page 3 of the Sun, for example, is also 40 years old and some might argue has remained a stable (albeit controversial) example of ‘soft porn’. Debates on sexualisation and commercialisation (which are not included in this essay but are contemporary and very relevant) show us that there are significant changes around sexual media. But also suggest that mainstream media is also likely to be a place where we might learn about all the things the author lists as hardcore – anal sex, BDSM, orgies etc. This makes it more difficult to categorise both what ‘porn’ is and where it ‘resides’. Which in turn makes it tricky to talk about causal effects of porn use. It is why we need critical voices looking at the quality of research in this area, challenging bad science, and focusing on where there is information about common social issues around sexually explicit material that require answers.

    The claim that ‘pornography is more exciting than satisfying’ seems to come with a lot of value judgement attached and taps into other debates on sex where porn use or masturbation are somehow less valid than other forms of sexual behaviour (commonly heterosexual penis in vagina sex). Regardless of how one feels about porn, avoiding setting up hierarchies of sexual experience would be helpful in a scientific essay on this subject. Or at least acknowledging this happens in both research and public discourse, why it occurs, and where that can be a problem. This is particularly important given much mainstream media coverage of porn and its effects (particularly around neurological issues) is so poor. We need far stronger social/science writing on this topic.

    Raising concerns about porn, or suggesting it is a fascinating and important area of study (which it is) is perfectly fine. Making claims that seem to go beyond robust data, with no clear references is problematic. Avoiding engagement in existing research on this issue that could tap into wider public discourses that medicalise and pathologise sexual behaviour are not helpful. It is unclear whether the author didn’t consider these issues or perhaps did but the edited version of their piece that appears here has not included them.

    This area remains a topical one. Groups like Onscenity http://www.onscenity.org are currently trying to look at this issue in a more critical way. Skeptics have tackled the evidence on porn http://www.youtube.com/watch?v=5UwMzcG2eW0 and this week and this week sees a large event discussing porn and other issues relating to sexualisation http://www.ioe.ac.uk/research/50360.html. It is unclear if the author or the judges who shortlisted this essay are aware of these events, nor the wider evidence base from the social sciences and humanities around pornography and related effects. I would hope they and others consider these before accepting theories about the effects of pornography that may be more problematic than they first appear.

    • 29 Nov, 2011 10:43 am

      Some great points there Petra.

      I will just add though that the writing by Marnia Robinson and her husband focus on heterosexual men’s use of porn and from what I have seen from Onscenity and the Pornified conference so far, there is still not a very strong critique of that stance coming out. ‘Sexualisation’ is mainly presented as the sexualisation of girls and women, by men and media focussed on men’s sexual pleasure.

      Jay Owens below speaks of the need for more evidence based research. And I really hope some of that research will challenge the gendered assumptions about pornography and sexuality that still prevail.

      • 29 Nov, 2011 11:18 am

        Quiet Riot Girl yes,you are right. This area of research is gendered, and the focus predominantly of the harms caused by heterosexual porn to women. Thoughtful debates on masculinity and sexuality exist but are often overshadowed by studies like those mentioned in the essay above. Jay is right about more critical research which certainly is needed. My concern with discussions around porn/brain plasticity (or related debates on addiction) is these reinforce gendered debates on sex which are unhelpful, restrictive, and frequently scientifically inaccurate. It is why I wanted more from this essay and Wellcome generally.

  3. 28 Nov, 2011 10:29 pm

    Agree with the above – the neuroplasticity thesis needs to be anchored by empirical research evidence if it’s going to further our verifiable knowledge about how people + porn works. Little bit disappointed in both the Wellcome and Dr Bennes, both of whom I respect.

    Yes, the cultural production of porn has changed in terms of images and cultural texts, that’s not disputable. But people are complex and not dictated to by culture – therefore the social and psychological impact of this change has to be researched, not assumed.

    Whether quant survey, qual interviews or something else, the questions to ask are essentially (a) has porn impacted your sexual desires and/or behaviours, and (b) have you observed porn having an impact on the people you have had sex with? [With the likelihood that people will be able to report more accurately on others’ behaviour rather than their own.]

    This also has to be asked in a non-leading way – which probably means asking about how people’s sexual desires and sexual experiences have changed over time, and then asking them to attribute possible causes (e.g. getting older, more experience, getting more comfortable with my body – and having watched X type or amount of porn).

    It’s evidence we need (more than theories) if we are going make decent decisions individually or societally about what porn means and does.

  4. 1 Dec, 2011 10:39 pm

    Coming at this from a neuroscientist background, I also have to take issue with some of the conclusions made in this essay. I’m afraid that a lot of this reminds me of some of the latest output of Baroness Susan Greenfield, in the way it takes basic/typical neuroscientific principles and weaves them into a narrative which effectively helps ‘demonise’ (for want of a better term) a specific bugbear. In her case, it’s video games or social networks, in this essay it appears to be porn.

    The Greenfield comparison is a relevant one, as I would personally argue that the cultural shift in porn preferences is more a technological phenomenon than a sociological one. 40 years ago hard core porn was largely available only through specialist shops or unofficial (and possibly illegal) means, and the famously and irrationally prudish British censors had much greater control over what was on offer. Now, that simply isn’t the case with the internet making porn much more readily available from anywhere in the world instantaneously. I’d argue (and have been reliably informed) that hard core porn has always been as graphic as it presently is, it’s just a lot more abundant now because it takes a lot less effort to get it. Cars are a lot faster now than 40 years ago, but this does not necessarily suggest a cultural/neurological sift in our desire for speed.

    I would also question the conclusions that porn has this great an impact on neural plasticity and appetitive reward systems. At the risk of being crass, the point of watching porn is usually masturbation, which (assuming it’s successful) does release the endorphin rush of the satisfying reward system. This system is already in place within the brain, so I’d argue that porn doesn’t have that substantial an effect. Arguably, if porn really did reduce our desire for genuine sex, then we should see evidence of less sex occurring in society, but I’ve not heard of such a thing reported. Granted, anyone who excessively repeatedly exposes themselves to one type of rewarding stimuli like porn does risk altering their brain morphology, but then Susan Greenfield uses the same argument about video games, and the same point is still valid; anything done to excess in this manner will impact on neuronal plasticity, porn is just one possible example. There may be those who are more sex obsessed and so enthusiastic about porn, but then a porn addiction is just as likely to be an effect rather than a cause of their behaviour. And without porn, it’s possible they’d seek satisfaction in more questionable ways.

    The tolerance for porn can also be explained in terms of simple habituation or associative learning paradigms, basic processes where the novelty of a stimulus is the main driving factor in provoking a neurological response. The more familiar porn is, the less of a response it get, causing the individual too seek out more ‘intense’ stimuli. There is no reason to think this wouldn’t have happened 40 years ago if the availability was there. But humans are also more complex than this argument or the essay gives them credit for. A rational person can tell the difference between images on a screen and a physical relationship with a close partner, to suggest that porn could somehow overrule this is seriously underselling the complexity of the brain. The brain is a lot harder to trick than that.

    There are plenty of other issues I could discuss here, but my overall point is that this piece seems to be motivated more by the social stigma of porn than the actual science of neuronal plasticity, and I’m a bit surprised that it made the Wellcome short list

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