The Cambridge University neuropsychiatrist Dr Valerie Voon has recently shown that men who describe themselves as addicted to porn (and who lost relationships because of it) develop changes in the same brain area - the reward centre - that changes in drug addicts. The study, not yet published, is featured next week in a programme on British TV - Porn and the Teenage Brain. Neurosceptics may argue that pictures of the brain lighting up in addicts tell us nothing new - we already know they are addicted. But they do help: knowing the reward centre is changed explains some porn paradoxes.
In the mid-1990s I, and other psychiatrists, began to notice the following. An adult male, in a happy relationship, being seen for some non-romantic issue, might describe getting curious about porn on the burgeoning internet. Most sites bored him, but he soon noticed several that fascinated him to the point he was craving them. The more he used the porn, the more he wanted to.
Yet, though he craved it, he didn’t like it (porn paradox 1). The cravings were so intense, he might feel them while thinking about his computer (paradox 2). The patient would also report that, far from getting more turned on by the idea of sex with his partner, he was less attracted to her (paradox 3). Through porn he acquired new sexual tastes.
We often talk about addicts as though they simply have “quantitative problems”. They “use too much”, and should “cut back”. But porn addictions also have a qualitative component: they change sexual taste. Here’s how.
Until recently, scientists believed our brains were fixed, their circuits formed and finalised in childhood, or “hardwired”. Now we know the brain is “neuroplastic”, and not only can it change, but that it works by changing its structure in response to repeated mental experience.
One key driver of plastic change is the reward centre, which normally fires as we accomplish a goal. A brain chemical, dopamine, is released, giving us the thrill that goes with accomplishment. It also consolidates the connections between neurons in the brain that helped us accomplish that goal. As well, dopamine is secreted at moments of sexual excitement and novelty. Porn scenes, filled with novel sexual “partners”, fire the reward centre. The images get reinforced, altering the user’s sexual tastes.
Many abused substances directly trigger dopamine secretion - without us having to work to accomplish a goal. This can damage the dopamine reward system. In porn, we get “sex” without the work of courtship. Now, scans show that porn can alter the reward centre too.
