What you can learn about the behaviour of dopamine from porn addicts, or any addiction for that matter
With Internet porn it’s easy to overstimulate your brain. Each search, each novel image, each surprising visual, each new genre, and sexual arousal itself all release dopamine in your reward circuitry. Dopamine is the gas that powers the reward circuitry and it equates with desire, anticipation, cravings, and wanting something in particular.
Unfortunately, too much stimulation causes some brains to protect themselves by decreasing their “sensitivity” to dopamine, and thus to pleasure, for a while. Obviously, if your brain does this and you are using porn frequently and heavily, your brain doesn’t ever have a chance to return to normal sensitivity. You may find yourself clicking to more extreme material to arouse your reward circuitry’s numbed pleasure center.
Over time, your brain adapts to this situation with measurable decreases in dopamine signaling. You want more, but experience decreasing satisfaction. This is an addiction process called desensitization.
Your reward circuitry is the barometer for “How exciting is this?” so if dopamine signaling (desire) is low, erections are sluggish. Erections only arise when dopamine signals flow from the reward circuitry to the hypothalamus.
If desensitization were the whole story, erections would be weak whether the stimulus were a girl, your imagination, or porn. But obviously it’s not the whole story, because porn still does the job. In fact, as you try to stop using, porn’s impact temporarily increases. This is where sensitized neural pathways come in.
Desensitization refers to a general dialing down of your responsiveness to all pleasure…a baseline change.
Sensitization refers to hyper-reactivity/excitement—but only in response to the specific cues your brain associates with your addiction. Over time, this dual-edged mechanism has your reward circuitry buzzing at the hint of porn use, but less than enthused when presented with the real deal.
So exactly how does sensitization arise?
In simple terms, sensitization involves two very normal brain mechanisms taken too far: long term potentiation (LTP), which is the strengthening of synapses, and long term depression (LTD), which is the weakening of synapses.
Long term potentiation (LTP) is the basis of learning and memory. It can be summarized as “nerve cells that fire together, wire together.” Memories arise in two steps. First, your reward circuitry signals that an experience is important by sending dopamine to your prefrontal cortex (PFC). The more dopamine the more importance your brain attaches to an experience.
Second, the PFC responds to your “This is important!” signal by
(1) knitting together everything associated with the reward, and
(2) forming a neural feedback loop heading back to the reward circuitry.
Thereafter, any thought, memory, or cue associated with a particular reward activates the pathway, and sets your reward circuitry a buzzin’. It could be smells associated with your favorite burger joint. For a tomcat it could be the hole in the fence that led to a female in heat. For a bird it might be seeing the guy who fills the birdfeeder. Its evolutionary purpose is to help you remember the who, what, where, when and how of sex, food and rock ‘n’ roll.
Importantly, the feedback loop doesn’t run on dopamine. It runs on glutamate. Both neurochemicals have the power to activate “Go get it!” signals in your reward circuitry.
Glutamate stimulation is why porn can still ring your chimes even when your reward circuitry has stopped responding to dopamine and real partners.
Reward circuit (dopamine) → PFC (associations formed) → feedback loop (glutamate) to reward circuit.
Sensitization, however, transforms this normal PFC → glutamate feedback pathway to the reward circuitry into a super-memory in three steps:
1. With sensitization, explicit memories (such as facts and events) transform into habits, which are known as implicit memories. Example: knowing how to ride a bike without thinking
2. Sensitized pathways are a non-dopamine mechanism for activating reward-circuitry neurons—come hell or high water. This sneaky feature seems to be at the core of all additions. Traffic jam on the main dopamine highway keeping you from feeling pleasure from real sex? No problem. You have another way to get home, but it’s only allowing one type of vehicle (stimulation): PORN.
3. Continued use of your addiction activates a third mechanism in the sensitization process: long term depression (LTD). The reward circuitry’s innate braking system (GABA) weakens, further amplifying the “Go for it!” glutamate signals. Instead of normal brain operation, which is more like city driving where you check for oncoming traffic at every intersection, your sensitized porn pathway is the autobahn. There are no traffic lights and porn is the only BMW M-5 on the road.
The master switch that triggers these addiction-related changes is the protein DeltaFosB. High levels of consumption of natural rewards (sex, sugar, high-fat) or chronic administration of virtually any drug of abuse cause DeltaFosB to accumulate in the reward center.
Note that addictive drugs only cause addiction because they magnify or inhibit mechanisms already in place for natural rewards. This is why the American Society of Addiction Medicine unambiguously states that food and sex addictions are true addictions.
DeltaFosB’s evolutionary purpose is to motivate us to “get it while the getting is good!” It’s a binge mechanism for food and reproduction, which worked well in other times and environments. These days it makes addictions to junk food and Internet porn as easy as 1-2-3.
It appears that desensitization eventually leads to loss of executive control (hypofrontality), another major feature of addictions.
Let’s say you decide to make the ultimate sacrifice and stop using porn. You’ll probably feel rotten for a while. Remember, your brain initially perceived your heavy porn use as a genetic bonanza. It thought you were making babies with each ejaculation. It laid down the super-memories so you wouldn’t abandon your “valuable” bevy of beauties (or whatever you were climaxing to).
Now, as you defy your brain by abstaining, your already low dopamine drops further
Worse yet, during abstinence the sensitized “goosing” pathways grow even stronger. It’s as if your pleasure center is screaming for stimulation…but only the addiction can hear the call.
During this “flatline” phase, a porn cue may still fire you up, and even trigger an impressive erection. This can fool you into thinking that porn is the cure for your sluggish libido. The real cure is to patiently wait for structures in your brain to catch up with your new direction. Meanwhile, all other stimuli, including your partner, are less arousing.
Despite their enormous power, sensitized pathways eventually lose their grip as your brain returns to normal and everyday pleasures become more satisfying…eventually the brain allows the sensitized pathways to weaken at the same time it strengthens the pathways related to other promising rewards (such as real partners).
- Gary Wilson
Related
NOTES - MY COMMENTS ON THE ARTICLE
I learnt so much in this article…thankyou.
I’m not into porn, but I’m into cognition and social cognition. I work as a collaboration lead in an organisation, so I’m interested in what makes people tick both individually and within group dynamics. Which is all related to other things like self-determination (intrinsic motivation, employee engagement, bias, trust in sharing with others)
Yes of course cognition is only one aspect of our behaviours…our behaviours are also influenced by the environment (parenting, family, friends, events). Just like nutrition isn’t the only thing that makes for good cognition http://bigthink.com/ideas/41955
I like how you tie it in with the PFC, which I learnt from another Psychology Today blogger, Christopher Bergland:
http://johntropea.tumblr.com/post/14916069492/how-does-the-dopamine-rewa…
“In a modern world we still get the same rush of dopamine when it comes to primal things like dating or salivating over a meal - but it becomes less automatic when trying to achieve goals that are not part of our primal instincts. We have evolved to have hard work, sweat and perseverance trigger the release of dopamine. Unfortunatlely, in a modern world these achievements are not viewed biologically as a matter of life or death and do not automatically release dopamine. Luckily, you can use your large prefrontal cortex and the ‘executive function’ to trigger the release of dopamine…”
I’m heavily into another blogger at Psychology today, Loretta Graziano Breuning
http://johntropea.tumblr.com/post/14309383783/dopamine-did-not-evolve-to…
“Happy chemicals did not evolve to surge all the time. Their job is to get your attention when something promotes your survival. They turn off soon after they turn on so they’re ready to get your attention to the next good thing.
If you haven’t learned to live with your unhappy chemicals, you might get into the habit of scrambling for another dopamine burst in any way possible. You seek the next promotion or the next party or the next donut or the next mountain or the next confrontation, depending on how your brain got wired. You create frustration, which means more unhappy chemicals and a more frantic quest to trigger happy chemicals.
This is the survival mechanism we’ve inherited. Old rewards don’t make us happy because the brain soon habituates to them. It takes what you have for granted and focuses its attention on new rewards. If you could get bigger and better rewards in every moment, you would never have to experience the core unhappiness of being a mortal human being. But that desperate seeking causes unhappiness of its own.”
Loretta also says:
http://johntropea.tumblr.com/post/12327167516/our-mammalian-limbic-brain…
“If you surged with dopamine all the time, your energy would be depleted when you really needed it. We evolved to save dopamine for those moments when an important goal is within reach.
People do all kinds of things once they find that it stimulates their endorphins, or their dopamine, or their oxytocin, or their serotonin.
Your happy chemicals evolved to ebb and flow. But if you attend to this feeling that something is wrong, it can preoccupy you. Your cortex will scan the environment for evidence that something is, in fact, wrong. And it will find evidence to confirm that feeling
Try as you might, you can’t control your environment in a way that ensures a steady flow of happy chemicals.
Yet it’s natural to desire more happy chemicals and to do everything possible to stimulate them. They evolved to motivate us to go toward things that promote survival. Natural selection created a brain that motivates you to promote your survival with happy chemicals. A brain that was happy all the time would not need to take survival action to feel good. Survival prospects would fall. Natural selection would weed out a brain that was happy all the time!”
And this from Athena Staik at PsychCentral
http://johntropea.tumblr.com/post/14454446034/feel-good-hormones-may-exp…
“These feel-good hormones may explain why certain behaviors are compulsively repeated, even toxic ones that merely escalate reactivity. They help lower the intensity of painful emotions – and thus can be addictive in nature, as they offer temporary, quick fixes that release some level of the feel-good chemicals.
It is no wonder that partners say and do certain things that are counterproductive or even downright destructive. At subconscious levels, it is to make themselves feel better.”
Do you agree that dopamine is not always meant to be surging?
If so, what about oxytocin…it’s not as easy as oxytocin nasal spray so everyone gets along is it…don’t we have to mean it, isn’t being human about growth and learning
Funny thought - So what about the “somewhat” opposite of this, pre-mature ejaculation…guys that would equally get excited by porn or the real thing too quickly…from their baseline, perhaps becoming a porn addict for a little while will balance their desensitization and sensitization scale
I wonder if there’s some sort of correlation here…
The toxo parasite breeds in a cats gut and is expelled with excretion, so the way toxo gets back into the cats gut is to make rats not fearful of the smell of cats. But the weird thing is the rats still have a fear system and are still scared of the usual things like bright lights and open spaces…some how toxo lasers out this one fear pathway.
Even further surprising is the rats are actually attracted to cat urine…see here:
http://johntropea.tumblr.com/post/3842909492/free-will-or-a-parasite-controlling-your-behaviour
“Now you take Toxo-infected rats, right around the time when they start liking the smell of cat urine, you expose them to cat pheromones, and you don’t see the stress hormone release. What you see is that the fear circuit doesn’t activate normally, and instead the sexual arousal activates some. In other words, Toxo knows how to hijack the sexual reward pathway. And you get males infected with Toxo and expose them to a lot of the cat pheromones, and their testes get bigger. Somehow, this damn parasite knows how to make cat urine smell sexually arousing to rodents, and they go and check it out. Totally amazing.”
This reminded me of the part in this article:
“If desensitization were the whole story, erections would be weak whether the stimulus were a girl, your imagination, or porn. But obviously it’s not the whole story, because porn still does the job. In fact, as you try to stop using, porn’s impact temporarily increases. This is where sensitized neural pathways come in.”
“Sensitization refers to hyper-reactivity/excitement—but only in response to the specific cues your brain associates with your addiction. Over time, this dual-edged mechanism has your reward circuitry buzzing at the hint of porn use, but less than enthused when presented with the real deal.”
Is toxo somehow causing sensitization in rats without the rats having to grow (or earn) this addiction themselves?
COMMENT G WILSON
I think I have those articles on my website. Amazing stuff. Toxo has the genes to produce dopamine, and the ability to rewire fear circuits related to approaching cats. But neither is sufficient to explain attraction to cat urine.
With lab animals, they find that “self-administration” can cause sensitization, whereas injections by handlers may not. How does Toxo mimic self administration AND sensitization to an external cue such as urine?
There’s a doctoral thesis for you.
(Source: psychologytoday.com)
