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 ordinary life operate independently of one another — sensory areas, motor areas, regions involved in memory and emotion and bonding — light up simultaneously, in synchrony, in a way rarely observed in any other state of consciousness. The boundaries between specialised regions blur. The brain becomes, briefly, an unusually unified system.
Sensory centres that process touch; motor centres that coordinate rhythmic movements of release; centres that release dopamine and other reward chemicals; centres that orchestrate the pituitary hormone cascade; certain centres of memory; centres that encode emotional bonding to a specific other person — all of these activate together, in a single great chord across the brain. There is no other natural state in human biology that quite resembles it.
The chemistry that accompanies this neural orchestration is equally remarkable. In the seconds leading up to orgasm, the brain releases a surge of dopamine — the neurotransmitter associated with reward, motivation, and the experience of joy. In the moments that follow, a different cascade begins: the release of endogenous opioids, the brain’s own morphine-like compounds, including the endorphins that produce profound calm and well-being.
"The combination — dopamine and endorphins together — is responsible for the unique character of orgasmic experience: simultaneous excitement and dissolution, pleasure and peace, intensity and release."
The Amygdala Stands Down Too
The endorphins released during this state are powerful natural analgesics. Pain that was present before — even chronic pain, sometimes severe — is reduced or absent during sexual experience, and remains reduced for some hours afterward. This has been demonstrated in formal studies of patients with chronic pain syndromes. The relief is real, even if temporary. The body, it turns out, carries its own pharmacy. Sexual experience opens the dispensary.
Bonding
The Bonding Aftermath
What Oxytocin Actually Does
In the period following orgasm — what Masters and Johnson called resolution — two further hormones are released in significant quantities: oxytocin and prolactin. These are sometimes called the bonding hormones, and the name captures something true. Oxytocin in particular is associated with feelings of attachment, affection, and trust. It is the hormone released in nursing mothers that drives the emotional bond with the infant. It is released in friendships and in long marriages during quiet moments of physical closeness. It is a fundamental ingredient of what we mean by love.
It is deeply significant that the human brain has evolved to release these specific chemicals at this particular moment. Sexual experience, in our species, is followed automatically by a flood of bonding chemistry. The intended evolutionary purpose, presumably, is to attach two individuals to one another long enough to raise the offspring that may result. But the mechanism, having evolved for that purpose, also serves a broader one: it provides one of the few reliable means by which two adult human beings can form deep emotional connection — not through words, not through shared activity, but through a chemical event in the brain that draws them, neurologically, toward one another.
Why It Matters
Beyond the Biological
The Overlapping Neuroscience of Peak Experience
The states that sexual experience can produce — joy, peace, fulfilment, connection, the dissolution of the boundaries of the self into the experience of another — are precisely the states that human beings spend their lives chasing through every other available means. We seek them in religion, in achievement, in nature, in music. They are rare, and they are precious. Sexual experience offers, for those who are able to receive it, a reliable and naturally occurring path to brief but genuine encounters with these states.
The brain mechanisms underlying these states are not unique to sexual experience. The same neural and chemical signatures — the quieting of the lateral surveillance areas, the release of dopamine and endorphins, the dissolution of ordinary cognitive boundaries — appear in modified form during other peak experiences: music played and heard at a high level, the deep absorption of artistic creation, the flow states of athletes and craftsmen, the states reported by experienced meditators. A life rich in such experiences, across all available domains, is a life that uses the equipment we have been given.
This also explains why excessively rigid or moralistic frameworks impair sexual function. The neurology requires a temporary release from internal surveillance. A worldview that maintains continuous moral evaluation of every act, every thought, every feeling cannot allow that release to occur. The result is not virtue. It is dysfunction — biological, measurable, and unnecessary.
The Wisdom of Vatsyayana, Confirmed
The wisdom of Vatsyayana, and of the older traditions he drew upon, was not in the technical details of sexual practice. It was in a fundamental orientation: that this dimension of human life deserved attention, study, refinement, and care — that it was worth thinking about with the same seriousness one might bring to philosophy, to ethics, to art.
We have spent several centuries trying to forget that. The neuroscience now suggests, in its own dispassionate language, that the older tradition was right. A clear-eyed engagement with this dimension of human experience — free of the inherited fears, the unnecessary shame, the cultivated misperceptions — is a legitimate path to depth, to connection, to the kind of richness that gives the years their meaning.
The neurobiology suggests it. The ancient wisdom of multiple civilisations also suggested it. They are saying, in different languages, the same thing.
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About the Author
A neurosurgeon by training, a writer by compulsion — and a student of the human condition by necessity. These essays explore what science, surgery, literature, and life have in common: the fragile, extraordinary act of paying attention.
