The Brain in Love: 12 Lessons to Enhance Your Love Life (9 page)

In women during their reproductive years, testosterone surges just before ovulation, in the middle of the menstrual cycle, lead many to a higher level of desire when they are most fertile. Some physicians believe that birth control pills may possibly be the cause of a decreased libido in many women because of how they interfere with ovulation to prevent pregnancy through the manipulation of levels of testosterone and estrogen. Low testosterone levels have also been associated with Alzheimer’s disease and other memory problems, heart disease, and lowered bone density. If you have a low libido and memory problems, it is critical to have your testosterone levels checked.

Estrogens

Estrogens are the sex hormones produced primarily by a female’s ovaries that stimulate the growth of a girl’s sex organs, as well as her breasts and pubic hair, known as secondary sex characteristics. Estrogens also regulate the functioning of the menstrual cycle. Estrogens are important in maintaining the condition of the vaginal lining and its elasticity, and in producing vaginal lubrication. They also help preserve the texture and function of a woman’s
breasts. Considering when women with deficient desire are given estrogen and testosterone separately, the increase in desire is not as dramatic as when they are given the two hormones together, estrogen is thought to play a synergistic role with testosterone in increasing lustful desire.

In women and men, estrogen is also produced in the brain; though the contribution of estrogen to male sexual behavior has not been completely established yet, researchers are speculating that estrogen may also be very important for sexual appetite in men. An unusually high level, however, may reduce sexual interest, cause erectile difficulties, produce some breast enlargement, and result in the loss of body hair in some men. Unfortunately all of us are being exposed daily to a large amount of “xenestrogens,” chemicals in the environment such as pesticides, which look like estrogen and bind to those receptors in the body. Also, inorganic chicken and beef may be injected with multiple hormones including estrogens to plump them up for the slaughterhouse. If you have the choice, it is better to select organic chicken and beef.

Nitric Oxide

Nitric oxide is a chemical released by the genitals when you are “turned on” that causes blood vessels to dilate and increases blood flow especially to the penis. Drugs like Viagra and Cialis work by stimulating the release of nitric oxide. Though these medications can work very well for some men, results of the studies that have been done thus far on women have not been compelling. Also, because these medications affect blood vessels, caution must be taken in giving them to individuals with blood pressure problems or heart disease.

Pheromones

Have you ever noticed how you have been attracted to the way someone of the opposite sex smells while another’s scent may completely repel you? Pheromones, scented hormones secreted by
sweat glands primarily in the armpits, are thought to attract the opposite sex. In 1991, a research group from Harvard University proved the existence of this “sixth sense,” or human vameronasal system. How these hormones work is not clearly understood yet, but they are thought to influence how humans mate, bond, and take care of their offspring. Women in college dorms, or who spend a lot of time together, develop synchronized menstrual cycles and pheromones are thought to be responsible for this phenomenon. In primitive times, scent was one of the first methods of communication, and it is still an important part of how humans relate and who they will want sexually. According to neurologist Alan Hirsch, smell also has a tremendous impact on attraction. “If you smell good, we want you closer; if you smell bad, we want you to go away. When you think about the sexual organ, you really should be speaking of the nose.” He goes on to say that we talk about love at first sight, when we really should be speaking of love at first sniff, because there’s a direct connection between the olfactory bulb at the top of the nose and the septal nucleus of the brain, the erection center. Sexual arousal is also associated with engorgement of the erectile tissue in the nose. Dr. Hirsch has treated patients who have smell and taste disorders, and found that almost a quarter of people who lost their sense of smell develop sexual dysfunction. Measuring penile blood flow with what looks like a small blood pressure cuff, he found that sexual arousal in men was enhanced by the smells of lavender and pumpkin pie. Doughnuts, licorice, and cinnamon were also on the top of the list. (I will discuss this topic in more depth in Lesson Nine, which covers aphrodisiacs.)

Infatuation Chemicals—
“I Can’t Get You Out Of My Head”
(Epinephrine, Norepinephrine, Dopamine,          
Serotonin, and Phenylethylamine)   

Mother Nature formulated a very powerful concoction when she created the potion of chemicals involved with infatuation. The biology is smart because if it weren’t for this forceful surge of
chemicals, the inhibitory centers in the brain (primarily the amygdala), which warn us of potential danger or heartache, would prevail and people would never meet, mate, and procreate. Some have described the infatuation stage as an “altered state of consciousness” or akin to being “intoxicated” or “under the influence.” People in this phase tend to sacrifice sleep, stay up late for hours talking with their lover on the phone, send abundant e-mails daily, and engage in behaviors that they wouldn’t typically do, such as skydiving when they are afraid of heights or eating sushi when the thought of raw fish has always made them gag.

Romantic love and infatuation are not so much of an emotion as they are motivational drives. They are part of the brain’s reward system. These feelings intensify to compel lovers to seek mating partners. The brain links these drives to all kinds of specific emotions, depending on how the relationship is going. All the while, our PFC is assembling information, putting the pieces of data into patterns, coming up with strategies, and monitoring progress toward “life’s greatest prize.” The chemicals that stimulate the motivation and drive system in the brain are the neurotransmitters epinephrine, norepinephrine, dopamine, serotonin, and phenylethylamine (PEA). These neurotransmitters play a role in the initial phase of attraction as well but it is really in the second phase of infatuation where their release becomes more active and predominant. Neurotransmitters are chemicals that help regulate the electrical signals between nerve cells in the brain. The brain is constantly seeking to keep itself balanced through increasing or decreasing amounts of these substances, some of which excite the body, for example when you see your new love from a distance and your heart starts to pound uncontrollably, and some of which calm the system and allow you to enjoy the moment, “smell the roses,” and have the “warm, fuzzy” feelings associated with a new relationship.

Epinephrine and Norepinephrine

Epinephrine and norepinephrine, produced in the adrenal glands, spinal cord, and brain, are considered excitatory neurotransmitters
because they cause that “adrenaline rush” feeling when the heart beats faster, blood pressure goes up, and the body is prepared to take action either in the face of a threat or in the presence of a positive stimuli such as a potential love partner. The feeling of zest and excitement comes from these chemicals as they help to facilitate both sexual arousal and orgasm. High levels of these chemicals are associated with anxiety, and low levels with depression. Chronic stress, low levels of the sex hormones estrogen, testosterone, and progesterone, a sedentary lifestyle, poor diet, and genetics can all lead to low levels of epinephrine and norepinephrine, creating interference with “the laws of attraction.” Certain medications, such as stimulants or supplements like the amino acid tyrosine, can help to increase levels of these chemicals in those who have a deficiency. Medications and forms of therapy including hypnosis and biofeedback are also used to decrease these levels when they get too high, such as when individuals refrain from asking someone who they find attractive out on a date because they are afraid they will get overly anxious, their palms and face will get sweaty, or they will fumble over their words.

Dopamine

The most important and well-studied neurotransmitter associated with infatuation is dopamine. Produced in the central part of the brain, dopamine is associated with pleasure, motivation, and concentration. It has been shown to work in the reward centers of the brain. Proper amounts are associated with healthy motivation and sexual drive. Individuals feel “sexy” when they have enough of this chemical. A study by Dr. Helen Fisher published in 2002 helps explain the activity of dopamine in the brain when people are falling in love. She and a team of experts recruited forty subjects who had just fallen in love—twenty who stayed in love, the other half who had recently split up. She put each of these people into an MRI tube with a photo of a sweetheart and one of an acquaintance. Each subject looked at the sweetheart photo for
thirty seconds, then—after a distraction task—at the acquaintance photo for another thirty seconds. They switched back and forth for twelve minutes. The result was a picture of the brain in love. There was increased activity in the right ventral-tegmental area. This is the part of the brain where dopamine cells project into other areas of the brain, including the basal ganglia, part of the brain’s system for reward and motivation. The sweetheart photos, but not the acquaintance photos, caused this to happen. In addition, several parts of the prefrontal cortex that are highly wired in the dopamine pathways were used, while the amygdala in the temporal lobes, associated with fear, was temporarily put out of commission.

While high levels of dopamine are associated with attraction, low levels are associated with certain types of depression, attention-deficit/hyperactivity disorder (ADHD), and excitement-seeking or high-risk-taking behavior. Both cocaine and stimulant medications, such as methylphenidate (Ritalin), have been shown to enhance its production. Bupropion (Wellbutrin) is an antidepressant that enhances dopamine availability to the brain as well as enhances sexual function. Also, certain amino acid supplements like tyrosine can be used to increase dopamine levels and potentially sexual function as well. I have seen both women and men benefit from Wellbutrin and/or amino acid supplementation either when sexual function has been diminished from low levels of dopamine or when substances like SSRI medications have suppressed sexual interest.

Serotonin

Serotonin is known as the “feel good” neurotransmitter and is produced in the midbrain and brain stem. Satisfaction with a partner and the positive feelings after an orgasm are to a large degree controlled by serotonin. Normal serotonin levels help people have healthy moods and motivation. Serotonin is involved with mood regulation and emotional flexibility. Low serotonin levels have
been associated with depression, anxiety, obsessive-compulsive disorder, impulsivity, and excessive activity in the brain’s anterior cingulate gyrus (ACG). Low levels have also been associated with new love. Unfortunately, this makes lovers vulnerable to high anxiety levels and moodiness, common in the initial stages of a relationship. When serotonin levels are low and the ACG works too hard, people tend to get stuck on certain thoughts or behaviors. Remember the last time you fell in love. All you could think about was your new love, and no matter how busy you were, you could always find time for her. Your moods were up when you thought about her and then down when she didn’t answer her cell phone the first time you called. You felt more reckless and your friends wondered about your judgment. Lowered levels of serotonin make you vulnerable to depression if the relationship ends prematurely.

In my clinical practice, I spend most of my time scanning the brains of people who need help. As part of my research, I scan many healthy people as well. Several years ago, one of my friends was scanned as part of our healthy-brain study. Several months later he fell madly in love. One day he dropped by my office to tell me about his new love. I could hear in his voice that he was so taken with his new woman that I did a repeat scan on him just to see his brain in love. The second scan showed significant increased activity in the anterior cingulate gyrus and basal ganglia, indicating his brain was literally obsessed with the woman; probably a measure of his serotonin levels would have revealed low levels at that time.

High serotonin levels can also be a problem and are associated with lowered motivation. Medications that enhance serotonin, such as selective serotonin reuptake inhibitors (SSRIs) like Prozac and Lexapro are notorious for decreasing sexual drive and function in part because recipients of these medications can lose interest if there is too much serotonin circulating in the brain, but also because these medications can decrease sensation in the genital areas, making it harder to achieve orgasm.

Dopamine and serotonin tend to counterbalance each other in
the brain. When dopamine levels are high, such as in new love, people tend to be motivated and driven toward dating behaviors that bring people closer together. Higher levels of dopamine cause lower levels of serotonin, which have been associated with obsessive thinking, hence the feeling of falling in love. When serotonin levels are high, people tend to have lowered motivation and an almost “I don’t care” attitude.

Phenylethylamine

Phenylethylamine (PEA), an adrenalinelike substance, the chemical found in chocolate, speeds up the flow of information between nerve cells and is triggered in the process of attraction to help us pay attention to the love feelings. PEA is known as the “love molecule” because it is what initiates the flood of chemicals into the brain along with norepinephrine and dopamine to create the feelings of euphoria and infatuation when we are highly attracted to someone.

Commitment Chemicals—“I Love You”
(Oxytocin and Vasopressin)          

For those of us who have had the wonderful experience of falling in love and being infatuated with someone, we also know that this amazing high and trancelike bliss does not last forever. We either progress into deeper love and commitment or make the decision to break apart and detach. Neuroscientists have determined that after a period of anywhere from six months to two years, the brain downshifts its response and the production of stimulating chemicals and levels of neurotransmitters like PEA start to drop off. It is the body’s innate wisdom to turn down the volume because it cannot maintain the lust-crazed state forever or people would eventually collapse with exhaustion. Several of my colleagues who do family and couples therapy note that a lot of unnecessary divorces and relationship breakups can occur during this time
because people mistake the lack of intensity and euphoria as a sign that they have fallen out of love. Also because individuals may feel a withdrawal from the chemicals of infatuation, they may look for other sex partners, alcohol, or other substances to try to re-create the high. Understanding this phenomenon in advance can really help partners anticipate this phase and help them move into the next phase of trust and commitment where true love really begins. Once you find an attractive partner, how does your brain decide if you want to keep him or her? Commitment is usually harder for men than women. Even though our goals are the same (continuity of the species, pleasure, and connection), women are more oriented to raising children. There is not one human society where men are primary caretakers for kids. Men and women are wired differently. Women have a larger limbic or emotional brain. It doesn’t mean that men are not essential in childrearing or that they won’t help. They just have different roles. Unless women have experienced emotional trauma, they are usually more ready to settle down and start a family. Men are often frightened by the responsibilities involved in raising children and being faithful to one woman, which is easier for men who have lower testosterone levels. An American study of over four thousand men found that husbands with high testosterone levels were 43 percent more likely to get divorced and 38 percent more likely to have extramarital affairs than men with lower levels. They were also 50 percent less likely to get married at all. Men with the least amounts of testosterone were more likely to get married and to stay married, maybe because low testosterone levels make men calmer, less aggressive, less intense, and more cooperative. The desire to commit to someone is strongly linked to two other hormones of emotional bonding, oxytocin and vasopressin.