The Brain of a Pornography Addict - a Picture of Natural Addiction

by Kaylin Magosin

$13 billion. One in five mobile searches. Over one billion total Internet browses since the start of 2015. These are all statistics for one of the hottest (pun-intended) topics of controversy – the pornography industry.

The prevalence of pornography usage in today’s society has led researchers to study its effects in the realm of emotional, behavioral, social and moral implications. However, beneath these environmental repercussions lie deeper biological implications on the human brain. Expanding neuroscience research into the field of pornography is beginning to suggest that natural processes in the brain can lead to something called “pornography addiction.”

Despite substance abuse often being touted as the main factor for addiction, neurobiologists are now supporting the idea of natural addictions, described as neurobiological processes involving the brain’s frontal region and its input directing the reward pathway in survival mechanisms, such as the need to eat and to reproduce in order to survive. Looking at addiction from this perspective, we can see that addiction can no longer be defined simply as a behavior that results from a stimulus-response reflex to a substance.

The American Society of Addiction Medicine defines addiction as “a chronic disease of brain reward, motivation, memory and related circuitry,” pointing to the mesolimbic dopaminergic reward pathway and the decision-making frontal cortex. This brings to light the complex neuronal processes occurring inside the brain of an addict.

A chief idea behind the neuroscience of addiction is that our brains are plastic, meaning they can rewire and reorganize themselves. Neurons, or brain cells, have the ability to form new connections as well as break old ones. Thus, the process of reward-based learning is essentially a rewiring of neuronal pathways in the brain in response to a stimulus. The greater the frequency of the stimulation, the stronger the connections!

For example, consider the classic experiment of Pavlov’s dogs. A ringing bell was paired with the expectation of food, and the dog portrayed increased salivation as a learned demonstration of its association between food and the ringing bell. This conditioning created a learned reward pathway, strengthening the neural connections in this context. Addictions operate under the same general principle. An increase in the frequency of a stimulus promotes greater neural rewiring, thus more reward-based learning and craving (in the case of pornography).

Nikolaas Tinbergen’s experiment in the 1950s showed that male butterflies preferred to mate with the artificially enhanced butterflies to the natural ones, describing yet another example of enhanced neural connectivity. In this situation, the novelty of the artificial females (the “better looking” ones) attracted the male butterflies. This drive to mate with the “best” butterflies is analogous to the drive for the “best” or most “hardcore” pornography—the more you seek, the more strongly your reward pathway is activated for that specific reward. The stimulus that was previously satisfying is no longer enough. Therefore, from Tinbergen’s experiment, it can be proposed that the more pornography one consumes, the more addicted he or she will become, even if the addiction is to an “artificial” person—in this case, the subject portrayed in the pornography.

With regards to the specific biological mechanisms involved in the limbic reward circuitry, it has been proposed that the protein DeltaFosB plays an important role. DeltaFosB has been shown to facilitate hyperconsumptive states of natural addiction, essentially allowing progressively increased use of the addictive substance, which in this case is pornography. By genetically manipulating the expression of DeltaFosB in mice, studies have shown that an increase in DeltaFosB causes an enhanced display of addictive hyperconsumptive behavior in terms of food, sex and wheel running.

In addition, DeltaFosB mediates changes in medium spiny neurons of the nucleus accumbens, a part of the ventral striatum, which is a component of the basal ganglia of the limbic system, the region responsible for emotion, memory and arousal. Specifically, the basal ganglia receives inputs modulated by the neurotransmitter dopamine, which regulates pleasurable reward. Upon exposure to sexual stimuli, dopamine floods the brain. Eventually, after continuous and excessive exposure to sexual stimuli, such as pornography, these dopamine receptors become “worn out” and eventually diminish. As there are fewer receptors and more dopamine, the brain cannot tell how much dopamine there really is. As a result, the brain craves more and more of the learned stimulus, continuing to produce more dopamine while losing sensitivity to this pleasure-inducing substance. This applies directly to pornography usage, pointing to the need for more and more pleasure-inducing stimuli in order to reach that intended level of satisfaction.

Another region of the brain affected by natural addictions is the frontal lobe, which is responsible for decision-making and control. A 2002 MRI-based study on cocaine addiction showed a volume loss of the frontal lobe in addicts. A similar study in 2004 was conducted on methamphetamine addicts and yielded similar results. Two years later, a third study of obese patients gave the same results yet again.

This research shows that natural addictions from endogenous processes (factors internal to the body) can have similar effects as addictions caused by exogenous substances. Therefore, it can be proposed that endogenous processes, including sexual ones, can cause impulsivity and compulsivity. In fact, a 2007 German study showed that “sexual compulsion can cause physical, anatomic change in the brain,” the first study to show such brain changes. Here, the research focused on pedophilia, indicating that volume reductions observed in parts of the frontostriatal brain seemed to form a neurophysiological circuit, not just specific to pedophilia, but one that "may also be involved in other deviant behaviors like addictive, impulsive or compulsive behaviors."

In light of expanding scientific evidence, we can propose that pornography has far-reaching effects on the brain. In today’s medical literature, there even exists such a medical diagnostic category for pornography usage—compulsive sexual behaviors (CSB).

Thus, attention should be devoted towards increasing evidence for the biological consequences of pornography usage. Such neurobiological studies and results must be shared in order to properly inform the public of the neurobiological consequences of pornography in today’s Internet-saturated society.

As we move into the future, with increasing access to the World Wide Web and controversial privacy constraints, it will become crucial to start the conversation on this undoubtedly widespread issue.