One would think that there is no aspect of the brain’s multitudinous biochemical majesty that lies outside of the interest of neuroscientists. There is an embarrassment of research riches packed into that 1300 grams of neural matter, each topic surely affording a unique avenue of insight into the nature of humanity that any neuroscientist would be glad to call their own. And that is true, nearly. A budding young scientist proposing to research the topics of memory, spatial perception, or task planning, or the neurochemical roots of addiction, will find the doors of funding flung wide open for their approach. However, until quite recently, this was decidedly not the case for the biochemical origins and aspects of what is for many of us the most important part of our biological lives: love.
To propose research into what love is, neurochemically, what biological systems foster it, and which systems its processes in turn support, was for much of the Twentieth Century to be met with derision. Love was deemed either too complex a phenomenon to admit of meaningful targeted research, or too soft and nebulous a topic to attract sufficient funding for long-term study. And so, while we spent decades honing our knowledge of how experiences get enshrined in long term memory, or why our sense of directional hearing is so woefully inadequate when compared with other animals, we spent shockingly little time (with some bold exceptions, such as 1969’s Interpersonal Attraction by Berscheid and Hatfield) answering the simple question, “What is Love, what does it do for us, and what happens when it is gone?”
It wasn’t until the late 1980s that a movement was founded which had as its goal the identification of the neuroscience underlying human interactions. Social Neuroscience, as that movement is known today, made its way into the larger consciousness as a result of a 1992 article by John Cacioppo and Gary Berntson, published in American Psychologist. Suddenly, the mental processes underlying social interactions were on the table as relevant and rigorous topics of research, inspiring a rising generation of students with the radical idea that one of humanity’s defining characteristics, our intricate social lives and the flood of joys and anxieties they bring with them, was a fit subject for research, including the individual whose studies into the neuroscience of affection attained such heights of fame that she was dubbed Dr. Love by those covering her work, Dr. Stephanie Cacioppo.
Cacioppo was born Stephanie Ortigue in a ski resort in the French Alps, the only child of two parents who were madly in love with each other. Her mother was a professor of economics, and her father was the manager of a frozen-food business, and together they demonstrated daily a romantic ideal of mutual dedication and support. Young Ortigue, for her part, was a person of solitude, who enjoyed her studies and challenging herself physically, but who never felt the social drive that seemed to characterize the adolescents around her. She was, as many only children are, something of a solitary dreamer, given to flights of imagination.
Perhaps because of her distinctly thoughtful character, she was the particular object of affection for her grandmother, who was Ortigue’s most reliable source of social comfort growing up. When Ortigue was nine years old, that grandmother died of a stroke, which inspired in the young girl a need to understand what had happened to the most important person in her life, in order to find a way to overcome it, so that nobody else would have to lose somebody as central to their lives as her grandmother had been in hers.
Ortigue entered the university system at an exciting time. The early 1990s saw not only the birth of the social neuroscience movement, but also the discovery of mirror neurons at the lab of Giacomo Rizzolatti. Between them, these two developments provided both the departmental motivation to look at the neuroscience of interpersonal relations, and a powerful explanatory tool for exploring the uniquely powerful empathy of primates (for more on mirror neurons, check out our piece on Tania Singer from way back in the day!)
Ortigue made the decision to do her PhD work at the University Medical School of Geneva, studying brain injuries and disorders, developing the all-consuming devotion to her research that would become the hallmark of the next two decades of her life. Sleeping too little and forming few social connections, all in the name of maximizing her time at work, she compiled over the early 2000s a portfolio of work covering a broad range of neural phenomena, including alloesthesia (in which sensations experienced on one limb are “felt” by the patient on the opposite limb), hemispatial neglect (in which an entire half of one’s visual field is ignored by the brain), color neglect, auditory hallucinations, induced speech arrest, and the neural origin of out-of-body experiences.
Over the course of her work in Geneva, she found that one thing which allowed patients with brain injuries to commit to therapy and succeed in rewiring their brain to compensate for lost functions was to tie that therapy into something that the patient felt passionate about. There seemed to be something about love and passion that engaged neural machinery which augmented the body’s self-repair processes. It was an intriguing phenomenon which she wanted to study further, and after surviving a barrage of professional advice to avoid the subject of love entirely in order to avoid committing “career suicide,” she eventually transferred to Dartmouth College in 2006 to do just that.
The mid to late 2000s, then, saw Ortigue producing the work which we most associate with her name today, and which earned her the title of “Dr. Love” in the popular press. She collaborated with Francesco Bianchi-Demicheli on a series of papers that sought to map the neural regions associated with love, affection, and sexuality, including early papers in 2006 on the neurophysiology of the female orgasm, and on “The Power of Love on the Human Brain,” followed by papers on the cerebral networks surrounding sexual pleasure in women, the role that mirror neurons play in allowing the individual members of a couple to expand their sense of selfhood, the factors that allow humans to understand the intentions of others, and the neuropsychiatry of sexual desire.
From 2005 to 2012, Ortigue (who became Stephanie Cacioppo upon marrying the afore-mentioned John Cacioppo in 2011) turned the power of fMRI imaging onto the question of how the brain experiences love, and how the neural machinery of love marshals resources that the body can use to improve performance on a wide range of tasks. As opposed to the old adage that Love Makes People Dumb, Ortigue found that love can make us cleverer and heartier. Individuals primed with the name of a loved one performed better on cognitive tasks than those primed with the name of celebrities or acquaintances. Looking closer at what regions of the brain are involved in love, Ortigue found not only those regions one might expect, ancient seats of emotion we have long known are involved in our more primal reactions to our surroundings, but regions of higher-order thought as well, including the angular gyrus, a relative newcomer on the evolutionary scene which has ties to language, autobiographical memory, and imaginative thinking.
Love, it turns out, is smarter than we think, or at least stimulates parts of our brain which might cause us to think quicker and act more imaginatively than we could when motivated by lower order attachments like friendship. During this roughly decade long period of study, Ortigue showed us not only how our body is augmented by love, but broke down the components involved in the process of falling in love – how do lust and desire shade into love, and how does our distribution of neural stimulation change in that process? What does your brain pay attention to when looking for a sexual mate, versus a lifelong partner? (Some of the answers to that question might not surprise you.) How do love and mirror neurons combine to allow us to know another person’s intentions, and to experience a loved one’s reactions to situations on an almost instinctual level, as if they were our own?
After marrying Cacioppo in 2011 and moving to the University of Chicago to work with him at the Brain Dynamics Laboratory, we see a definite shift in Ortigue’s research focus, towards topics more aligned with his research interests. Over the course of the 1980s, while Ortigue lived out her life as the dreamy apple of her grandmother’s eye, Cacioppo was developing the field of social neuroscience, culminating in his work on how loneliness is experienced by the body and mind. This was important work for a world in which people grow daily more isolated from each other, and Ortigue’s papers of the late 2010s increasingly focused on the neuroscience of loneliness.
John Cacioppo passed away in 2018, and in 2022 Stephanie published Wired for Love: A Neuroscientist’s Journey Through Romance, Loss, and the Essence of Human Connection which tells the story of her early research into brain injuries and the neuroscience of love, interspersed with autobiographical material centered on her relationship with John. She continues her work at the University of Chicago Brain Dynamics Laboratory, directing her group in studying the impact of emotions on human performance, and further delineating the physical and psychological effects of loneliness on individuals.
Lead image of Dr. Stephanie Cacioppo, Ph.D., via The University of Chicago Brain Dynamics Laboratory