This Is Your Brain on Sex Read Online Free PDF Page A

for “domestic propensities” such as amativeness, conjugality, and friendship. Photo by the author.
[Individuals] may be intellectually wise; they may be technically honest as to property and social rights, but if they lack Parental Love they will not want children; if they lack Conjugal Love they will not want marriage. If they have strong Amativeness, they may desire society through action of that faculty. . . . Free love animals and free love men lack something which does them no credit. Conjugal Love, the special, life-long, individual and exclusive mating, is human, honorable, natural, and the only sound philosophy of sexual mating.
    Basically, if you were looking for love in the Victorian age, you had better hope to have your chaperone distracted long enough for you to get a good feel of a potential mate’s occiput before committing to anything permanent. Accordingto phrenologists, one misplaced lump or chasm could make all the difference to your future happiness.
    No matter that the spot that Gall and Spurzheim denoted as the seat of that dratted amativeness is not even adjacent to the brain. It lies next to some sinuses and veins, a good distance away from any gray matter. This little inaccuracy illustrates one of the many problems with phrenology. While Gall and Spurzheim’s basic idea that bits of brain underlie different functions fits right in with today’s neuroscientific theories, their focus on both expansive, ill-defined traits (just what might an organ for “firmness” or “sublimity” refer to?) and the exterior as opposed to the interior of the skull means it is not a scientifically sound theory.
    Although phrenology eventually crashed and burned in both the popular and scientific dominions, the concept of function localization managed to stick around. For the next two centuries scientists focused on trying to pinpoint areas of the brain associated with memory, language, attention, and movement by observing patients with brain damage and animal models as well as using a variety of electrophysiological techniques. Even these “simple” concepts were difficult to study in the brain. Something like love, with its associated erotic, cognitive, and goal-directed behaviors, was too much for many researchers to even consider studying, especially since it was unclear what love might be. Was it an emotion, like sadness or fear? A drive, like hunger or thirst? A human construct to justify sex that had no basis in biology whatsoever? No one knew for sure. The fact that scientists could not pin it down made love seem impervious to serious scientific inquiry—and put it on the research back burner for more than a century.
    Scanning Love
    In the late twentieth century advances in technology enabled researchers to transcend one of phrenology’s biggest failings. Neuroimaging techniques like computerized axial tomography (CAT) scanning, single photon emission computed tomography (SPECT), and positron emission tomography (PET) allowed scientists to look inside the skull and observe the living, working brain instead of relying on cranial bumps, autopsy specimens, oranimals. These new approaches provided more detailed analysis of localized brain function. But it was not until the early 1990s, when a new technique called functional magnetic resonance imaging (fMRI) hit the scene, that neuroscientists could look deeper and attempt to localize something as shambolic as love.
    How does fMRI work? It is all about the blood flow. Like all organs in the body, the brain needs blood in order to work. Even the smallest area of neural activity is accompanied by an influx of oxygenated blood. The brain uses that oxygen to facilitate function and then sends it on its way. This point is key for measuring activation using the fMRI. Oxygenated blood has different magnetic properties from deoxygenated blood. A large spinning magnet in the fMRI can track where the blood goes and how that blood flow changes over time. By following