Why Women Have Sex by Cindy M. Meston, David M. Buss Page B

in love carry their emotional ‘burden’ like a snail’s house into the laboratory of a physiologist.” And on the basis of their findings, the research team concluded that passionate love is like “mental chaos.”
    In 2003, a decade after Niels Birbaumer’s discovery, Andreas Bartels and Semir Zeki, two neuroscientists in London, began scanning the brains of young lovers to see what it means to “fall in love.” They selected seventeen men and women who met the criteria for being “truly, deeply, and madly in love” and observed their brains using a functional magnetic resonance imagery, or fMRI, scanner, which is able to record changes in blood flow to various parts of the brain. When nerve cells in the brain are active, they consume oxygen. Oxygen is carried to the brain by hemoglobin in red blood cells from nearby capillaries. Hence, blood flow to the brain and amount of brain activity are closely related.
    As the participants’ brains were being scanned, the researchers showed them pictures of either their beloved or nonromantic friends. Only when they were gazing at the photographs of their loved ones did the participants’ brains show intense activity in areas associated witheuphoria and reward—and
diminished
activity in brain regions associated with sadness, fear, and anxiety. In fact, the pattern of brain activity that occurred when the participants viewed their lovers was not unlike the pattern of brain activity seen when a person is under the influence of euphoria-inducing drugs such as cocaine. The brains excited with love also showed decreased activity in regions associated with critical thought, which might explain why people who are acutely in love often appear to be “spaced out.” Or maybe, as the study’s authors suggest, when a person decides he or she is in love, critical thought to assess the loved one’s character is no longer considered to be necessary.
    The “love is a drug” connection has also been noted by psychiatrist Michael Liebowitz of the New York State Psychiatric Institute, who compares passionate love to an amphetamine high. Both can create a mood-enhancing giddiness, and withdrawal of either can cause anxiety, fear, and even panic attacks. Indeed, the body releases a host of chemicals when a person first falls in love—dopamine, norepinephrine, and especially phenylethylamine, or PEA, which is considered a close cousin to amphetamine. The “natural high” caused by these brain chemicals, unfortunately, does not last forever. Liebowitz believes that is why some people, whom he calls “attraction junkies,” move from relationship to relationship seeking their next “love high.”
Love, the Mental Disorder
     
    In addition to all the wonderful emotions passionate love can cause—euphoria, excitement, contentment—it can also cause intense emotional turmoil. People in love often describe feelings of anxiety, depression, and despair when they are not with their loved ones—even when they are only separated for a relatively short period of time. They tend to spend hours and hours obsessively thinking about their loved ones in much the same way that a person diagnosed with obsessive-compulsive disorder, or OCD, experiences intrusive thoughts.
    In the late 1990s, psychiatrist Donatella Marazziti and her colleagues from the University of Pisa in Italy speculated that people who are passionately in love and people who suffer from OCD may have something in common—a decrease in the brain chemical serotonin. Decreasedlevels of serotonin have long been linked to depression and anxiety disorders such as OCD, and antidepressants such as Prozac work primarily by trying to increase the body’s serotonin levels.
    To test their hypothesis, the research team selected three separate groups of men and women. One group consisted of people who had fallen in love within the past six months but not yet had sex, and who obsessed about their new love for a minimum of four hours a day. A