Eros in the Brain

— Dr Jaydev Panchawagh  ·  MVD Surgery Centre, Pune Your brain is designed for this experience — and the neuroscience of what happens inside it, moment by moment, is more extraordinary than anything the ancient texts imagined. The History A Subject We Have Never Stopped Thinking About From Ancient Treatises to the Scanning Room There is one experience we have not yet considered in our journey through the brain. It is, in some ways, the most fundamental of all — the one without which none of us would be here. It has been celebrated, suppressed, theorised about, written into poetry and sacred texts, hidden in the dark corners of human imagination, and elevated to the status of art. For as long as humans have been recording anything at all, it has commanded profound cultural attention. I am speaking of sexuality. Of what the modern neuroscientist calls the neurobiology of sexual experience. For much of recorded history, this subject was deliberately obscured. Medieval clerics across many traditions — Christian, Islamic, and in certain periods, Hindu — pushed the topic into shadow. They moralised it. They surrounded it with shame. They deployed the accusation of sexual impropriety as a weapon, and they cultivated, in the populations they governed, the conviction that this most natural of human experiences was something to be feared and apologised for, rather than understood. This was not always the case. The ancient Indian tradition treated sexuality as a legitimate domain of intellectual and aesthetic inquiry — even as a domain of craft and art. References appear in the Vedas and the Puranas. By the time Vatsyayana wrote his Kamasutra — sometime between 200 BCE and 200 CE — the subject already had a long scholarly tradition behind it. His book was not, as popular imagination sometimes has it, a mere catalogue of technique. It was a treatise on the conduct of an entire dimension of human life: its emotional texture, its ethical responsibilities, its place within the broader pursuit of a meaningful existence. A Telling Observation The mystic Osho once remarked that across all his hundreds of volumes — on the Bhagavad Gita, on Ashtavakra, on mystics from every tradition — the only book the world reliably remembered was From Sex to Superconsciousness. The reason, he observed, lay not in his writing. It lay in the unconscious of the society receiving it. The reopening of sexuality as a domain of serious inquiry, in the modern West, dates only to the late nineteenth century. Havelock Ellis, Alfred Kinsey, Masters and Johnson — each pushed the subject further into the light. But these early researchers were largely confined to studying the body: what happened to the genitals, the heart rate, the breath. The brain was beyond their reach. The technologies that would allow scientists to watch the brain in the act of experiencing sexual arousal did not yet exist. Now they do. And what they have revealed deserves careful attention. The Neuroscience What Happens in the Brain During Arousal The Superego Steps Down Masters and Johnson identified four phases of the human sexual response: arousal, plateau, orgasm, and resolution. Each of these, we now know, corresponds to a distinct pattern of activity across the brain. Begin with arousal. The most striking finding from imaging studies of the past two decades is that, during sexual arousal, certain regions of the brain become less active, not more. Specifically, two regions in the front of the brain — the lateral orbitofrontal cortex and the lateral prefrontal cortex — show a marked reduction in activity. To understand why this matters, consider what these regions normally do. These are the parts of the brain that perform moral self-monitoring. They evaluate behaviour against internal standards of correctness, propriety, and ethical permissibility. They are, in essence, the neuroanatomical substrate of what Sigmund Freud called the superego — the internalised voice of every parent, teacher, religious authority, and social code that has ever shaped us. They are the parts of the brain that say: not now. Not here. Not this way. Not at all. “During sexual arousal, these regions go quiet. The superego steps back.” The constant internal evaluation that accompanies our every action eases its grip, briefly, allowing the experience to unfold without the running commentary of self-judgement. This is not incidental. It is, almost certainly, a necessary feature of the system. Sexual experience, as nature has designed it, depends on a temporary release from the cognitive frame of moral surveillance. Without that release, the experience cannot occur in its full form. The Amygdala Stands Down Too A second region also relaxes during arousal: the amygdala, that small almond-shaped structure deep in the temporal lobe that governs anxiety, vigilance, and threat-detection. Modern life keeps the amygdala chronically activated in most of us — scanning for danger that, in our evolutionary past, was real and present, and that today arrives largely via news alerts and social comparison. Sexual arousal, in conditions of safety and genuine connection, produces a marked reduction in amygdala activity. The body’s threat-detection system, briefly, is permitted to stand down. Now consider what happens when these regions do not relax — when the superego does not loosen its hold, when the amygdala remains hypervigilant. This is the neurobiological signature of much sexual dysfunction. Patients who carry deep convictions of sexual shame often show, on imaging studies, persistent activity in the lateral prefrontal regions during attempts at intimacy. The superego refuses to step back. The experience is, neurologically speaking, prevented. Key finding The mystic Osho once remarked that across all his hundreds of volumes — on the Bhagavad Gita, on Ashtavakra, on mystics from every tradition — the only book the world reliably remembered was From Sex to Superconsciousness. The reason, he observed, lay not in his writing. It lay in the unconscious of the society receiving it. Orgasm At the Moment of Orgasm — An Expansion The Chemical Symphony What happens at the moment of orgasm is among the most striking findings in all of neuroscience. It is, in a word, expansion. Brain regions that in