You won't regret it!
(Yes, that was me encouraging you to masturbate.)
Making Neurons Sexy: A Review of Sexual Activity and the Brain
Living in the United States, we are constantly bombarded by the hyper-sexualized media of the current generation. From radio to television to film, we are consistently reminded of just how salient sexual activity is in our lives. Radio hosts have become progressively open, no longer hesitant to utilize sexual innuendo as a form of humor and television shows have presented increasingly sexual content. Try as you might, it’s nearly impossible to escape the sexual content we are subjected to on a daily basis. Perhaps this overexposure begs the most basic question: why? Why is sex so fascinating that we have been able to capitalize on its existence in all outlets of mass-media?
The answer to this question could appear in many forms. One such assertion maintains that sex is healthy. Take migraines, for example. Research by James Couch in women experiencing migraine symptoms (ie. fatigue, moodiness, neck pain) found that sex at the onset of the migraine led to a reduction in symptoms (Harzog 2007). A separate position suggests that sex is beneficial for stem cell research. Prolactin, a hormone released following sexual intercourse, has been used in laboratory settings to stimulate the production of neurons in the olfactory bulb (Wood 2003). Furthermore, prolactin has been used to generate new brain tissue following stoke damage (2003). However we interpret our fascination with sexual conduct, it still remains that sex is an integral part of human life. The ideas that sex is healthy and scientifically beneficial are perhaps adequate. Yet, looking across the many layers of sexual function, there seems to be an underlying, biological reason for our obsession. It may be that a survey of neurobiological research is necessary to understand the many facets that compose this important aspect of our lives.
The following will examine how sex looks in the brain as function of the major implicated pathways, what deviates from normal sexual function in sexual addiction, and how various treatment methods work in standardizing sexual compulsivity on the neural level. Risks and benefits of sexual activity will also be observed. By exploring such aspects, loopholes or shortcomings may be identified for further research in the field of sexual activity.
To grasp the subsequent material, it is important to understand the most imperative areas of the brain that are implicated during sexual arousal and intercourse. Normal sexual functioning, though vastly different across all individuals based on social and environmental experience, requires the functional processing of both central erotic arousal- taking place in the human brain- and the arousal of the genito-pelvic region (Levin & Wagner 1986). When aroused in unison, these two areas of the body work in a mutual positive feedback loop which eventually leads to orgasmic discharge in the genito-pelvic region (1986). These areas are mediated through interpersonal experience and subjectivity, as well as the limbic brain; by integrating these regions, sex can be described as both a peripheral function and a brain response (Hiller 2004).
The most relevant of these imperative areas may be the interaction between the prefrontal cortices and the hypothalamus. The prefrontal cortices, the portions of the brain that are related to every motor response and chemical response in the body (Hiller 2004), are responsible for compartmentalizing every unique experience in the life span, one of which is sex. The hypothalamus then is responsible for the integration of hormone release during sexual behavior and arousal. Particularly, the hypothalamus is responsible for the synthesis of the peptide hormones vasopressin and oxytocin (Hiller 2004), both of which have been extensively researched in the neurophysiology of sexual bonding- especially the latter. Oxytocin has been shown to regulate noradrenaline, dopamine, and prolactin, in the brain (Hiller 2004; Insel 1997; Panskepp 1998); all three have been associated with brain reward.
Oxytocin appears to have quite an influence throughout the primary areas of the brain involved in sexual functioning. Though originally thought to be present only in the pituitary gland, oxytocin has also been shown as present along neurons in the spinal cord and the brain stem (Herbert 1994). This peptide hormone, most pertinent to the current survey, has also been shown to play a critical role in orgasmic stimulation. Across all male subjects in Murphy et al. (1990), oxytocin levels raised an average of 30% at the point of ejaculatory emission. Similarly, Carmichael et al. (1987) found an increase of nearly 60% (2.5pg/ml to 4.4pg/ml) in oxytocin levels in female participants at the point of orgasm (Hiller 2004).
Research that focuses on positive symptoms of sexual behavior, such as increased levels of oxytocin and other peptide hormones, is not the only methodology relevant to the survey of sexual functioning. It is just as beneficial to this examination of research to look at the functional differences in subjects with abnormalities in the primary areas of neural sexual functioning.
Sexual function can vary greatly after serious brain trauma or damage to the cells relevant to normal sexual functioning; a great deal of literature has looked at the differences in sexual functioning in subjects with traumatic levels of brain injury (Kreuter et al. 1998; Levin and Wagner 1986; Ponsford 2003). Most succinctly stated, “human sexuality encompasses biological, physical, cultural, and psychosocial dimensions of personality and [behavior]. [Traumatic Brain Injury] TBI may disturb any or all of these dimensions (Ponsford 2003).” Results have been consistent with Ponsford’s speculation that TBI affects multiple dimensions of the individual. In her 2003 research, over 50% of participants having experienced TBI reported significant sexual changes in the 5 years following the traumatic incident; sexual performance, sexual satisfaction, and sexual desire all saw significant decreases across subjects (2003).
Similar results were presented in Kreuter et al. (1998) with regard to satisfaction. Half of the participants reported being dissatisfied with their current sexual activity after the traumatic brain injury. Research suggests that this may be a function of a lesion on the prefrontal cortices or the hippocampus; both suggestions fall well in-line with the research highlighted above. Furthermore, nearly a quarter of all those having experienced traumatic brain injury reported a decreased sexual desire, erectile function, orgasmic activity, ejaculation, and intercourse frequency (1998). It should be noted that the participants who experienced brain trauma could have lesions on the prefrontal cortices, hypothalamus, or slight lesions on the brainstem; two of these areas are relevant to the synthesis or production of oxytocin, the peptide hormone that appears to be linked in many of the critical regions for sexual function.
Another crucial area of the brain that is necessary for normal sexual functioning is the medial amygdala. Heaton and Adams (2003) posit that the amygdala works as an organizer of sorts to help the individual determine a suitable, sexual mate. The amygdala also plays an important part in releasing neuropeptides, such as oxytocin and vasopressin, during sexual activity (Heaton and Adams 2003).
The medial preoptic area (MPOA) is also an implicated region of the brain used in sexual functioning (Heaton and Adams 2003). Research implies that the MPOA is the area of the brain that is responsible for the regulation of sexual activity in both males and females (2003). The MPOA is linked to the nucleus paragigantocellularis (nPGi) through periaqueductal gray and, in recent research, has been linked to the neural pathway responsible for sex hormone regulation.
Specific neurotransmitters concentrated in the MPOA also play a big role in sexual functioning. Cells in the MPOA have very high concentrations of dopamine receptors that are likely facilitated by “the activation of alpha2 and alpha1 adrenoreceptors (Heaton and Adams 2003). The activation of these receptors has been shown to act parallel with the stimulation of the penis and erectile function. Moreover, dopamine has been attributed as an award for sexual activity by being released in the brain following male ejaculation (2003).
Oxytocin and the implicated pathways in the brain may be responsible for the neural functioning of sexual behavior; but, there are other factors that play a role in such actions. Of the concepts used to understand sexual functioning and why we strive to engage in such behavior, the idea that motivation may influence our desire for sexual activity is perhaps the most intuitive.
On the neural level, serotonin and dopamine work in an inhibitory – excitatory loop to produce motivation for sexual behavior. Dopamine works to excite motivation toward sexual activity while serotonin works as an inhibitory response (Heaton and Adams 2003).
It is pertinent then to understand where sexual motivation comes from on a symbolic level and we how we understand it to function. Barry Singer and Frederick Toates (1987) posit that sexual motivation follows common incentive models of behavior. These models, as described by the authors, typically follow several generalizations. First, “incentives trigger motivated behavior (1987).” In sex, this could pertain to something as such as an orgasm. The incentive is the orgasm itself, while the stimulation of the clitoris or penis is the motivated behavior. Second, “incentives inflame motivation by producing affect, an interaction with an internal depravation-satiation state (1987),” and such incentives will be guided through motivation by available cognitive maps. To exemplify, the incentive of achieving an orgasm would be guided by both satisfaction of desire and cognitive processes. Singer and Frederick further explore this model by comparing it to hunger, or drive and appetite, and use these terms as metaphorical language to explain sexual motivation. One primary allusion they make is to abstinence. Men and women both note increased sex drive with abstinent behaviors (1987), much like the increased desire for nourishment when experiencing hunger. While the model presented by Singer and Toates certainly reflects the motivations behind satiating our desired states, it does so without regard to the positive or negative aspects of motivation.
Though no term currently defines impulsive, addictive, hyper, or any other negative sexual activity, research has been conducted to look at the motivation of such behavior (Kalichman & Rompa 1995; McBride, Reese, & Sanders 2008). Compulsivity can be regarded as a negative motivation behind most deviant sexual activity. Sexual compulsivity refers to an individual’s lack of control over their own sexual behavior. In most cases, the behavior of compulsive persons impairs functioning by promoting sexual acts that surpass the judgment of the individual. Scales like the Sexual Compulsivity Scale have been used demonstrate that hypersexualized behavior and sexual preoccupation positively correlate with negative outcomes of sexual activity (Mcbride, Reese, & Sanders 2008). Also, high scores of sexual compulsivity correlated positively with negative cognitive outcomes (2008). These outcomes, deriving from sexually compulsive behavior, can range from pessimistic thoughts to self loathing. In one particular case study, Wagner (2009) discovered that her sexually deviant patient reported high levels of maladaptivity across a few categories. Abandonment/instability, defectiveness/shame, and emotional inhibition had the highest ratings across the dimension of dysfunctional symptoms. The defectiveness/shame category seems especially relative in comparison to the withdrawn, unavailable nature that accompanies many of the other symptoms of sexual addiction (2009).
Like sexual compulsivity, sexual addiction is a negatively maintained behavior that an individual has little to no control over. According to Patrick Carnes, the executive director of Pine Grove Behavioral Health and Addictive Services in Hattiesburg, Mississippi, sexual addiction is perfectly comparable any other addiction (Untreated Sexual Addiction 2008); addiction to drugs and alcohol are especially similar. In his words, “addictions don’t just co-exist, they interact with each other (2008).”
Barbieri (2008), asserts that addiction utilizes three different brain pathways to function. The first is the arousal neuropathway that concerns stimulation and intensity; the second is the numbing neuropathway that concerns calming, sedative processes; the third is referred to as the fantasy neuropathway which allows addicts to “escape reality through a trance like state (2008).”
Carnes (2008) highlights that many researchers may attribute addiction to certain dispositional characteristics, commonly cited as ‘addictive personalities;’ there is evidence, though, that there is much more to the issue than personality type. In his defense of this assertion, Carnes states, “It’s a matter of what happens in the brain when you access the pleasure centers.” In his citation, he notes that the same areas of the brain that see increased activity under MRI scanning also light up in other addicts; the same area for a cocaine or gambling addict when they are high or engaging in risky activity will see similar increased activity when a sex addict is seeking to act on their compulsive behavior (2008). Though the subjects of Carnes’ research are drawn from the same program he directs, there are other ways in which sexual addiction is observed outside of treatment facilities. The Internet is also providing researchers with a new topic to explore.
The World Wide Web has certainly changed the way we communicate over the past decade, and Mark Griffiths (2001) suggests that this may be truer for sexual communication than any other form of social communication. He posits that “Internet sex is a new medium of expression where factors such as perceived anonymity and disinhibition may increase participation (2001);” the availability of sexual content on the Internet does not discount this assertion either. Internet sexual addiction has even become a commonplace term, often alluding to individuals who have committed Internet sex crimes such as harassment and cyberstalking (2001).
While some Internet sex addiction can come in more serious forms, such as those previously listed, others are rather harmless such as masturbatory addiction or orgasmic addiction. Many of these addictions have been listed beneath three defined Internet Addiction typologies (Griffiths 2001). First, the recreational user, is the individual who is not typically seen as at risk for Internet Addiction, but rather as a person who accesses online sexual material for entertainment purposes or curiosity. Second, the at-risk user, is the individual who may not have developed a sexual addiction without the introduction of the Internet. And third, the sexually compulsive user, is the individual that uses the Internet “as a forum for the sexual activities (Griffiths 2001).”
As these typologies increase from recreation to compulsivity, the self-image and sexual dysfunction of the individual are negatively affected (Griffiths 2001). These feelings of increased sexual dysfunction, decreased self-image, and lowered self-esteem are also characteristic of traumatic brain injury patients as listed above. This is of curious mention as there may be an opening here for research to expand the literature on any correlations between sexual addiction and individuals suffering traumatic brain injury.
For as many ways a person can experience sexual addiction, there appears to be an equal amount of ways for an individual to seek help or assistance with recovery. Ranging from drug treatment to therapeutic practices, there does not seem to be any shortage of programs or methods to be used in the normalization of sexual functioning.
One method described by Barbieri (2008) involves what she refers to as the URGES approach, or Urge Reduction by Growing Ego Strength. The URGES approach attempts to create a dissociated identity state of the ego by fragmenting the addict’s ego state into a stored experience and a dissociated experience (2008). By treating the ego as two separate entities, the therapist can then treat the addict’s fragmented ego as individuals that are looking for a fixed connection. In an addict’s case, the connection appears to be severed because of their severe compulsive behavior (2008).
Another external treatment is discussed at length in Tays et al. (1999) research on the sexual addiction model in the treatment of sex offenders. This treatment essentially falls back on one goal: the prevention of relapse at all cost. Furthermore, the treatment builds off the idea that recovery from sexual addiction can only begin when the addict acknowledges their own powerlessness (1999), a premise that is characteristic of many addiction programs across the world.
As the current review comes to a close, it’s of great importance to reiterate the information presented. Hopefully, the examination of how sex looks in the brain as a function of the major regions involved, the deviations made from normal sexual functioning in sexual addiction, and the various treatment methods available will provide some light for why sex has become such an integral part of our culture. Perhaps even further investigation will benefit from the aspects of the field of sexual activity identified here today.