Hockenbury Discovering Psychology 5th txtbk

334 CHAPTER 8 Motivation and EmotionFOCUS ON NEUROSCIENCERomantic Love and the BrainWhen it comes to love, it’s been said that the brain is the mosterotic organ in your body. Indeed, being head over heels in loveis an emotionally intoxicating brain state. Do the overpoweringfeelings of romantic love involve a unique pattern of brainactivity?Using functional magnetic resonance imaging (fMRI) to detectbrain activity, researchers Andreas Bartels and Semir Zeki (2000)investigated that idea with 17 love-struck young adults, all professingto be “truly, deeply, madly in love” with their romanticpartner. Each participant was scanned several times while gazingat a photo of the romantic partner. Alternating with the “love”Feelings of euphoria are just one of the many sensations, thoughts, and emotions thataccompany moments of impassioned, romantic love. As is shown in the fMRI scan, romanticlove also produces a unique pattern of activation in the brain.IPCscans were “friendship” scans taken while the participant lookedat a photo of a good friend who was of the same sex as theloved one.Bartels and Zeki’s (2000) results suggest that romantic love activatesbrain areas that are involved in other positive emotions,such as happiness, but in a way that represents a unique pattern.Shown here is a side-to-side fMRI brain scan depicting some ofthe brain areas activated by romantic love. Compared to lookingat a photo of a close friend, looking at a photo of one’s romanticpartner produced heightened activity in four brain areasassociated with emotion, including the anterior cingulate cortexCP(not shown), caudate nucleus (C),putamen (P), and insula (I).Given the complexity of the sentimentof romantic love, the researcherswere surprised that the brain areas activatedwere so small and limited to sofew regions. (Perhaps this lack of extensivebrain activation explains whylove-struck individuals are sometimesoblivious to everything except the objectof their infatuation.) Nonetheless,the four activated brain areas offersome insight into the intoxicating effectsof romantic love. Why? Becausethese are the same brain areas thatare activated in response to euphoriaproducingdrugs, such as opiates andcocaine. Clearly, there seem to besome close neural links between romanticlove and euphoric states.Emory University psychology professor Frans de Waal (1995, 2007), who has extensivelystudied bonobos, observes that their frequent and varied sexual behaviorseems to serve important social functions. Sexual behavior is not limited to fulfillingthe purpose of reproduction. Among the bonobos, sexual interaction is used toincrease group cohesion, avoid conflict, and decrease tension that might be caused bycompetition for food. According to de Waal (1995), the bonobos’ motto seems tobe “Make love, not war.”In humans, of course, sexual behavior is not limited to a female’s fertile period(Buss, 2007). Nor is the motivational goal of sex limited to reproduction. A woman’sfertility is regulated by monthly hormonal cycles. Some, but not all, women alsoexperience monthly fluctuations in sexual interest and motivation. However, thesechanges are highly influenced by social and psychological factors, such as relationshipquality (Thornhill, 2007; Gangestad & others, 2007). Even when a woman’sovaries, which produce the female sex hormone estrogen, are surgically removed orstop functioning during menopause, there is little or no drop in sexual interest. Inmany nonhuman female mammals, however, removal of the ovaries results in a completeloss of interest in sexual activity. If injections of estrogen and other female sexhormones are given, the female animals’ sexual interest returns.In male animals, removal of the testes (castration) typically causes a steep drop insexual activity and interest, although the decline is more gradual in sexually experiencedanimals. Castration causes a significant decrease in levels of testosterone, thehormone responsible for male sexual development. When human males experience