Neuroscience of Pornography
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Pornography Intervention - A Training Resource
By Jim Messina, Ph.D., CCMHC, NCC, DCMHS-T
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In 2005, a landmark paper described all addiction as a dysfunction of the mesolimbic reward centers of the brain. Addiction occurs when pleasure/reward pathways are hijacked by exogenous drugs such as cocaine or opioids, or by natural processes essential and inherent to survival such as food and sex. The same dopaminergic systems include the ventral tegmental area with its projections to the nucleus accumbens and other striatal salience centers (Hilton & Watts, 2011).
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VTA-NAc pathway and the other limbic regions cited similarly mediate, at least in part, the acute positive emotional effects of natural rewards, such as food, sex and social interactions. These same regions have also been implicated in the so-called ‘natural addictions’ (that is, compulsive consumption for natural rewards) such as pathological overeating, pathological gambling, and sexual addictions. Preliminary findings suggest that shared pathways may be involved: (an example is) cross sensitization that occurs between natural rewards and drugs of abuse (Hilton & Watts, 2011).
Depiction of the brain's reward circuit highlighting the role of
the striatum and its anatomical connections
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Ventral Striatal Reward Pathway
this circuit starts and ends in the brainstem with the release of dopamine. Activating these “reward cells” with stimulation (e.g., pornography, sex, drugs, food, etc., causes them to transmit dopamine to other regions in the cortex and subcortex such as the striatum. This reinforces the drive for future reward seeking behaviors.
These signals converge to a set of cells in the nucleus accumbens, which is essential for determining the motivational significance of the reward stimulus, causing the person to think, “Mmmmm that was fun; I’ll do that again.”
In cases of extreme compulsive pornography use, simply showing still pictures to the compulsive pornography user will engage this reward circuit. The same is true for people addicted to eating: showing them pictures of food can reengage the same
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In 2010 two studies described the effect of sexuality on neuroplasticity.
- one study, sexual experience has been shown to induce alterations in medium spiny neurons in the nucleus accumbens similar to those seen with drugs of abuse.
- Another study found that sexuality specifically increases DeltaFosB in the nucleus accumbens, and serves a role as a mediator in natural reward memory. This study also found that overexpression of DeltaFosB induced a hypersexual syndrome.
DeltaFosB may thus become a biomarker to assess the state of activation of an individual’s reward circuitry, as well as the degree to which an individual is ‘addicted’, both during the development of an addiction and its gradual waning during extended withdrawal or treatment (Hilton & Watts, 2011).
In 2007, a study looked specifically at pedophilia, and demonstrated almost identical finding to the cocaine, methamphetamine, and obesity studies. It concluded for the first time that a sexual compulsion can cause physical, anatomic change in the brain, the hallmark of brain addiction. A preliminary study showed frontal dysfunction specifically in patients unable to control their sexual behavior. This study used diffusion MRI to evaluate function of nerve transmission through white matter. It demonstrated abnormality in the superior frontal region, an area associated with compulsivity (Hilton & Watts, 2011).
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The Brain’s Neurochemicals Impacted by Compulsive Pornography Use
A Summary from Covenant Eye’s: The Porn Circuit: Understand Your Brain
and Break Porn Habits in 90 Days by Sam Black, 2013.
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Dopamine
Dopamine Dopamine has many powers. Dopamine focuses one’s attention on whatever task is at hand and motivates the person forward. It activates or enhances rewards circuitry that make one feel good, and it also plays a major role in memory. It helps people to recall what is important in their environment, and to remember the appropriate response to a stimulus. It fuels the tension and craving for meeting a need. That’s why dopamine is released in response to all drugs of addiction, and plays a role in many disorders affecting motivation and attention such as obsessive-compulsive disorder and behavioral addictions. Essentially, dopamine helps the brain remember what is interesting and how to respond to it. It focuses the mind on a specific task while other concerns are ignored. It provides a neurological reward that feels good, and assists in cravings for more of the activity.
DeltaFosB has been implicated as a critical factor in the development of virtually all forms of behavioral and drug addictions. In the nucleus accumbens, DeltaFosB functions as a "sustained molecular switch" and "master control protein" in the development of an addiction. In other words, once "turned on" (sufficiently overexpressed) DeltaFosB triggers a series of events that ultimately produce an addictive state (i.e., compulsive reward-seeking involving a particular stimulus); this state is sustained for months after cessation of drug of choice use (including pornography) due to the abnormal and exceptionally long half-life of DeltaFosB. DeltaFosB in the nucleus accumbens medium spiny neurons directly and positively regulates drug self-administration and reward sensitization through positive reinforcement while decreasing sensitivity to aversion.
Norepinephrine
Norepinephrine is a neurotransmitter often associated with stress and the fight-or-flight response, helping people to be more alert. It also acts as a hormone for sexual arousal and sexual memory, and it helps people burn emotional experiences in their minds. Whether it’s a wonderful sexual experience with one’s spouse or a provocative sexual image, the information is stored for easy recall with the help of norepinephrine.
Oxytocin
Oxytocin is often referred to as the bonding hormone, and big releases arrive when mothers and fathers hold their newborn babies. It is often called the cuddle hormone because oxytocin levels rise when a couple snuggles, hold hands, or express other forms of intimacy. Oxytocin is one reason a kiss is so powerful. It also plays a big role in sexual bonding to one’s partner and triggers the contractions during male orgasm. It is for this reason that married couples are encouraged to enjoy face-to-face sex that provides as much skin contact as possible for the greatest release of the bonding chemical. Because oxytocin is also released in climax, it can have a negative impact for the porn user. Instead of bonding to a real mate, the porn viewer’s brain bonds to the image, video, or situation, especially when the activity is reinforced through repetition.
Vasopressin
Working in concert with oxytocin, vasopressin also encourages the feelings of bonding and is slowly released during sexual activity and at climax. As with oxytocin, the release of vasopressin during porn viewing and masturbation works to cement a person’s attachment to this behavior.
Testosterone Often cited as the male hormone (although women have it in lesser amounts), testosterone dramatically increases sexual arousal and desire, It is a hormone that is released in men throughout the day, but when sexual cues are picked up by the brain the testes increase production. Pornography (and the mental fantasizing that it enables) crafts a brain that constantly generates testosterone and heightens sexual desire. With this ever-present sexual desire, the brain is ready to interpret any signal (external or internal) and ramp up the perceived need for sexual activity. Men with strong feelings of commitment to their spouse tend to have lower testosterone levels. This may be a reason why these men may be less likely to commit adultery.
Because testosterone is slow to dissipate, men who habitually view pornography cause their own chemical imbalance. This high testosterone level increases their sexual awareness far above normal. Sexual fantasies are sparked by everyday objects and even modestly dressed women are seen as provocative.
Endogenous Opiates
People were designed to have an amazing sexual experience. The body produces natural or endogenous opiates, which during climax provide pain relief and a sense of transcendence and euphoria. This is an opium like substance, naturally produced by the body.
Serotonin
Serotonin is released after climax and brings feelings of calm, wellbeing, and satisfaction. High serotonin levels also decrease sexual motivation. These factors help explain why men are often accused of being ready for a nap after sex.
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Graphic of How Compulsive Pornography Use Mimics Other Addictions in the Brain
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Video on How Compulsive Pornography Use Mimics Other Addictions in the Brain
Here is a Ted Talk Video which explains this process:
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A 2014 study was conduction on Visual sexual stimulation (VSS) and explicit penile–vaginal penetration images (PEN), both of which are powerful route into the brain’s core emotional circuitry. A recent review of VSS brain imaging experiments led to the identification of a sexual interest or saliency network that seems to primarily support fast and early processing of VSS, that is, before objective or subjective sexual arousal become obvious. The core elements of this ‘early’ sexual network are:
- Amygdala
- ventral striatum
- anterior insula
- posterior orbitofrontal cortex
- perigenual anterior cingulate corte
The study’s findings were:
- First revealed that many parts of the brain responded to pornography (PEN) in the same way they responded to highly disgusting (DIS) stimuli. This was supported by the finding that the elicited disgust to PEN explained much more variance in PEN-induced brain activity than the elicited pleasure toward the same stimuli.
- Second, women with relatively negative (i.e. disgust-related) implicit PEN associations had the strongest PEN-related brain responses.
These findings delve into the complexity of processing VSS, and unveil the important modulatory role of disgust to these specific penetration stimuli, at least in women (Borg, de Jong & Georgiadis, 2014).
In 2014 the first-ever brain-scan study of online porn users, was conducted at the Max Planck Institute for Human Development in Berlin, researchers found that the hours and years of porn use were correlated with decreased grey matter in regions of the brain associated with reward sensitivity, as well as reduced responsiveness to erotic still photos with:
- significant negative association between reported pornography hours per week and gray matter volume in the right caudate
- reduced functional activity during a sexual cue–reactivity paradigm in the left putamen
- Functional connectivity of the right caudate to the left dorsolateral prefrontal cortex was negatively associated with hours of pornography consumption.
The negative association of self-reported pornography consumption with the right striatum (caudate) volume, left striatum (putamen) activation during cue reactivity, and lower functional connectivity of the right caudate to the left dorsolateral prefrontal cortex could reflect change in neural plasticity as a consequence of an intense stimulation of the reward system, together with a lower top-down modulation of prefrontal cortical areas. Alternatively, it could be a precondition that makes pornography consumption more rewarding (Kuhn & Gallinat, 2014)
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The American Society of Addiction Medicine (ASAM) formally expanded their definition of addiction in 2011 to include both behaviors and substances: Addiction is a primary, chronic disease of brain reward, motivation, memory and related circuitry. Dysfunction in these circuits leads to characteristic biological, psychological, social and spiritual manifestations. This is reflected in an individual pathologically pursuing reward and/or relief by substance use and other behaviors (Love, Laier, Brand, Hatch & Hajela, 2015). There is a Three Stage Model of Addiction which includes:
- Binge/intoxication
- Withdrawal/negative affect
- Preoccupation/anticipation
Stage 1: Binge/intoxication
Different classes of drugs activate the reward system through different means, however, the universal result is a flood of dopamine in the NAcc (reward center). This results in acute positive reinforcement of the behavior that initiated the flood. In this impulsive stage, this positive reinforcement results in addictive related learning associations. Neuroplastic changes begin to occur, however, as the continued release of dopamine in the NAcc leads to an increase in dynorphin levels. Dynorphin, in turn, decreases the dopaminergic function of the reward system, resulting in a decrease of the reward threshold and an increase in tolerance.
Stage 2: Withdrawal/negative affect
The dopamine flood has run its course, and there is activation of the extended amygdala, an area associated with pain processing and fear conditioning. The resulting negative emotional state leads to activation of brain stress systems and dysregulation of anti-stress systems. This leads to a decreased sensitivity to rewards and an increase in the reward threshold, which is called tolerance. This further progresses to negative reinforcement as the individual continues to engage in the addictive behaviors to avoid the negative affect associated with withdrawal. A second component of the reward system comes into play here: the mesocortical dopamine pathway. Like the mesolimbic DA pathway, the mesocortical DA starts in the VTA, however it terminates in the frontal cortex. Specific affected areas within the prefrontal cortex include the dorsolateral prefrontal cortex (DLPFC), responsible for key components of cognition and executive function, and the ventromedial prefrontal cortex (VMPFC) responsible for components of inhibition and emotional response. Taken together, the mesocortical dopamine pathway affects the cognitive component of reward processing
Stage 3: Preoccupation/anticipation (craving)
The neuroplastic impairments expand beyond the mesocortical dopamine pathway into other regions of the prefrontal cortex responsible for motivation, self-regulation/self-control, delayed reward discounting, and other cognitive and executive functions. This leaves the individual vulnerable to reinstatement of the behavior, and two primary mechanisms have been identified; cue-induced reinstatement and stress induced reinstatement. Numerous neuroimaging studies substantiate this model, and these impairments are the source behind the “chronic relapsing disorder” element of the medical definition of addiction (Love, Laier, Brand, Hatch & Hajela, 2015).
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The Processes involved in the Neuroplasticity of the Brain
A Summary from Covenant Eye’s, The Porn Circuit: Understand Your Brain
and Break Porn Habits in 90 Days by Sam Black, 2013.
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The lifelong ability of the brain to wire and rewire its neurocircuitry is referred to as brain plasticity or neuroplasticity. The brain can increase or decrease the strength and number of synapses that communicate an emotion or feeling. This allows information or memories to flow more or less quickly.
This brain neuroplasticity also operates under a dynamic of “use it or lose it.” Do an activity more often and the brain will create neural pathways that make an activity easier to think about and complete. In creating neural pathways of porn use, repetition matters. Sexual activity launches major excitation in peoples’ brains, so it takes less repetition to build these porn pathways than it would to engrain cravings for other activities. Because porn provides a state of arousal, the brain also creates pathways that make initial arousal easier. Suddenly, porn and sex with a partner aren’t the only experiences that are arousing. As the porn pathways deepen, people in everyday life become objects of sexualized fantasy, and inanimate objects, clothing, and situations not designed for sex become sexually charged. How does this happen here are the processes involve:
Sensitization
A person who uses a pornographic image or story and masturbates for the first time begins a learning process of how to respond to porn in the future. With repetition the brain responds not only to the initial stimulus, but also to related stimuli. After a person becomes sensitized, very little is needed to trigger a response; a superhighway is connected to the rewards circuitry. This superhighway has many entrance ramps; sexual cues are seen everywhere and sexual fantasizing comes easy.
Triggers
Cigarette smokers can name a list of activities that spark a physical and mental desire for a smoke: drinking a cup of coffee, finishing a meal, sipping alcohol. These cues are called triggers, and when presented the brain gets a shot of dopamine that motivates a person to smoke, ingest nicotine, and fire the rewards circuitry of the brain.
Triggers also surface for porn and masturbation, and these sensitization cues can vary greatly from person to person depending on their gender, marital status, environment, and the types of porn and activities they use. Simply being home alone is enough to prompt many people to rush to their computer in search of porn. Some people lie awake at night, taunted with thoughts of getting up to view porn online and masturbate while the family sleeps. Why? Because they hold not only memories of using the computer for porn, but also of opportunities of secrecy, and even of getting up or staying up for a late-night fix.
These compulsive feelings are engrained from repetitive and powerful experiences. Dopamine flows easily in response to the learned pornographic trigger driving a person to act out, and the sensitized neural pathway leads easily to the rewards circuitry where opiates fire.
Desensitization
Though not true for everyone, many porn users find they need a greater amount or more intense porn to activate a state of arousal. The brain has decided after multiple porn excursions that this amount of dopamine is excessive. So, it has reduced the amount of dopamine in response to porn, and it has reduced the number of dopamine receptors for the neural circuits associated with porn use.
To escape this desensitization, people, and men especially, expand their pornographic tastes to more novel stimuli. What was once considered hardcore — a heterosexual couple engaged in intercourse — is now considered mundane, and varied forms of sex mixed with force, violence, and humiliation are now fused into today’s pornographic scripts.
Hypofrontality
Compulsiveness is a good descriptor of hypofrontality. Many porn users feel focused on getting to porn and masturbating even when a big part of them is saying, “Don’t do this.” Even when negative consequences seem imminent, impulse control is too weak to battle the cravings.
Summary of these processes
When a man sees his partner or pornography and is sexually stimulated, including imagination, his arousal is increased and his thoughts are focused through dopamine, testosterone, and norepinephrine. If sex or self-sex is pursued, these chemicals further focus his brain’s attention and narrow his thoughts on the sexual experience. These and other chemicals are also active in women during arousal, but in addition, perceptions, feelings, lengthy memories, and cognitive choices play a larger role.
During sex or masturbation, people get the sexual version of tunnel vision as more of these initial chemicals are combined with the slow release of oxytocin and vasopressin. Worries and concerns often fall away and the mind focuses on sexual release. The contractions of orgasm are connected to the brain’s release of endogenous opiates. As well, these opiates and dopamine shut off the portions of the brain responsible for anxiety, adding to the euphoria and the removal of fear. Then the brain receives serotonin, adding feelings of wellbeing and satisfaction. All of those hormones and neurotransmitters are actually interacting with the physical brain and its neural connections.
Through this process of learning, the neural circuits for a porn habit are sensitized, becoming broad superhighways with multiple on-ramps. These on-ramps are the direct result of a sensitivity to sexual cues that are seen in a growing variety of stimuli. The pornographic brain sees cues for arousal everywhere and because porn is part of the regular diet, testosterone keeps men especially on high alert.
When sexual cues are strong enough, dopamine spurs the pornography user to act out, which releases more of the neural chemicals that focus attention. In men, the neural pathway for masturbation leads to a quick release of opiates during ejaculation.
Meanwhile, as this highway grows more engrained, often people become desensitized to the pornography they have been using and seek more images or porn that are more novel. As this tolerance expands, people often become disgusted with their own pornographic pursuits…but do it anyway, broadening the cues that lead to arousal.
When pornography uses boast that they are pushing the envelope by introducing new, harder themes, what they don’t say is that they must, because they have been building up a tolerance to their usual content, So when the temporary escape has passed, many look at themselves and see the widening and higher banks of their pornographic stream. Their lives, both sexually and non-sexually, seem shallow and covered with algae. The dam has long been broken and so many once beautiful things are uprooted.
(Black, 2013).
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Reference for this section are at: REFERENCES on this site
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