Open Loops

The science of heartbreak: why losing love feels like withdrawal

They spent entire days without human contact and their mental distress, use of mental healthcare, and antidepressants increased acutely.

— Science, 2026 (Emanuel, Harrington & Pallais, “Home alone”)

Your silence today is a pond where drowned things live

I want to see raised dripping and brought into the sun.

— Adrienne Rich, “Twenty-One Love Poems,” IX

I. The Open Loop

Your heart keeps time to other hearts. It does this without consulting you, the way it handles most of its business, and the other hearts in question belong to the people you have let in close enough to matter. Your pulse, your hormones, the chemical tide that decides whether you sleep tonight—some fraction of all of it gets set by somebody else’s nervous system, humming away across the breakfast table, regulating a body you thought was yours alone.

Lewis, Amini, and Lannon, three psychiatrists writing in A General Theory of Love, gave this murmur between nervous systems a name: limbic regulation, which is a lab-coat way of saying two mammals spend all day quietly adjusting each other’s heart rate, hormones, and sleep. A lover walks into the room and someone’s blood pressure drops. We are open systems, leaky at the edges, quietly run by people who have no idea what they’re doing.

We call this love, and we have called it that for as long as anyone has sung anything, a few thousand years before the fMRI arrived, whirring. Science shows up after the fact and confirms what the songs already knew: that a person can become a physiological necessity. That you can need someone the way you need iron.

The trick is that it never feels like regulation. It feels like wanting them there. It feels like the kitchen is better with them in it and faintly haunted when they go. The machinery tucks itself inside the longing and runs silent, which is its genius and, later, its cruelty.

Because a closed loop makes no noise. You no more feel your heart being steadied than you feel a chair taking your weight—until the day the other is gone and the whole jury-rigged apparatus starts dropping signals, and you discover what held you up by the exact dimensions of its absence.

II. The Witness

A Day in Orient

In front of dark, rough fir trees,

grass with pale yellow fronds,

seeds eager to fly. They may

grow in the sand, but

wind of birds may derail.

Startled by lines drawn so

effortlessly. Beauty contained

in a cup on my beach bag

the red stripes aligned with

the drape of the leather handles.

And you just unaware of the

necessity of this drawing. We

lean against the grey log

pecked by termites, their

bullet holes matching the

diameter of our pens,

and pencils.

The line you instruct is

confident. Don’t hesitate

because ink doesn’t shrink

back in practice. Bold, loopy

be aware of the music

in what you see. Reflect

back the sound of the

trees as they vibrate

the light toward you.

You can create a shadow

on my bag as your

drawing bleeds into our

day. We cover ourselves

with the sheets of

paper when we sleep

and the lines cross

inside our eyelids

neon, pastel shimmering

Like the see, I can

do this.

You are so good. Deeply

and in a way that

shows no knots a

perfect plane of

chestnut wood the

grains all attentive

to your curves no

marks of branches

just smooth loopy lines.

III. What Closes the Loop

You are the sky, I am the lake … A drop of desire ripples out of the center of the sky.

— Vi Khi Nao, The Vanishing Point of Desire

A general feature of both oxytocin and love is the capacity to modulate more primitive defense systems including threat or fear.

— Carter, 2022, Comprehensive Psychoneuroendocrinology

Two things, named apart in the first breath—sky, lake—and then a drop falls into the one and it’s the other that ripples, and I can’t keep them separate after that, I’ve tried. The sky is in the lake. The lake is holding the sky. Which surface the desire belongs to stops being a question you can answer. That’s the part nobody tells you about being regulated by another person: you don’t feel the regulating. You just forget to be afraid. And here is Carter, choosing her words with a scientist’s care: the other person, she writes, can modulate our more primitive defense systems. Modulate. Sit with it and the precision opens up—tune, adjust, turn the dial on the threat and the fear, the old equipment we hauled up out of the reptile dark long before anyone was tender to anyone. What she means is that another person reaches past the thinking mind to the vigilance underneath and steadies it. Someone gets that far inside you, to the animal, and you let them. Which Nao knew, of course—that after a while you cannot say where one of you ends.

IV. What Chemistry Confirms

Laughter that makes my own

heart beat fast. If I meet

you suddenly, I can’t

speak—my tongue is broken;

a thin flame runs under

my skin; seeing nothing

hearing only my own ears

drumming, I drip with sweat;

trembling shakes my body

and I turn paler than

dry grass…

— Sappho, fragment 39, trans. Mary Barnard

Activation specific to the image of the beloved occurred in areas associated with … craving and emotion regulation and included the ventral tegmental area (VTA).

— Fisher et al., 2010, Journal of Neurophysiology

She sees the face and comes apart, and lists it as she goes—the tongue quits, the skin goes to flame, the eyes shut down, a green paleness the color of grass. She isn’t reaching for romance. She’s transcribing her own body, system by system, in the order they fail, which is the most honest thing a body in that state can do, and the honesty is the romance. Twenty-six centuries later they slide someone who feels that way into a scanner and show her the face and watch the ventral tegmental area (VTA) light up—the part of the brain that commands hunger and thirst, the wanting that keeps us reaching for what we need to stay alive. Craving, the paper says, and seats the beloved in the same booth as drugs and meals. Sappho had no map of the midbrain. She had fire and the failing tongue and no impulse to look away from either. The VTA is the room where her tongue breaks. Somebody just needed a magnet big enough to knock on the door.

V. The Tearing

in an afternoon of stone and saltpeter,

armed with invisible razors you write

in red illegible script on my skin,

and the wounds dress me like a suit of flames,

I burn without end, I search for water,

in your eyes there’s no water, they’re made of stone,

and your breasts, your belly, your hips are stone,

your mouth tastes of dust, your mouth tastes

like poisoned time, your body tastes

like a well that’s been sealed…

— Octavio Paz, Sunstone, trans. Eliot Weinberger (New Directions)

Feelings of social pain can be re-experienced or ‘relived,’ even when the painful episode has long passed.

— Eisenberger et al., 2015, PLOS One

There’s no far side for our poet to escape to. He burns without end in agony, razors cutting, the flames on his skin, and no cool morning after where he gets to describe it from a safe distance. When he goes looking for relief, he reaches the body that used to be the water and finds it gone to stone. Breasts, belly, hips: stone. The mouth that answered now tastes of dust, of poisoned time. The whole of her a well somebody sealed. And he keeps reaching anyway, dying of thirst at a spring he knew intimately before.

The same circuit that makes an infant scream when her mother leaves the room, the wiring every mammal is issued at birth, is redirected over years onto a lover. The face doesn’t have to be a mother’s. The scream is the same scream. And the intensity does not fade, because the wiring still keeps us alive by regulating our bodies’ rhythms, making separation unbearable. Our poet is years out, his whole life rebuilt, in a new city with new sheets, and the pain slams back in at its full original heat, his suit of flames fitted, his thirst clawing, time poisoned. This is the cost of being a mammal. To be wired for warmth and closeness and the long safety of another body in the bed is to be wired, in the very same circuit, to come apart when the other body is torn away. Reptiles without limbic systems eat their young. But when we lose our person, we live in agony and eat ourselves from the inside out.

VI. Reason’s Plank

…And I, and Silence some strange Race

Wrecked, solitary, here—

And then a Plank in Reason, broke,

And I dropped down, and down —

And hit a world, at every plunge,

And Finished knowing—then--

— Emily Dickinson, #280 (Johnson)

I can taste the tin of the sky --- the real tin thing.

Winter dawn is the color of metal,

The trees stiffen into place like burnt nerves.

All night I have dreamed of destruction, annihilations ---

An assembly-line of cut throats, and you and I

Inching off in the gray Chevrolet, drinking the green

Poison of stilled lawns, the little clapboard gravestones,

Noiseless, on rubber wheels, on the way to the sea resort…

— Sylvia Plath, “Walking in Winter” (Collected Poems)

The loss of a partner results in physiological and psychological risk factors across species. Rodents experience a reduction in oxytocin (OT) release accompanied by an increase in corticotropin-releasing factor (CRF), as well as elevated heart rate.

— Blumenthal & Young, 2023, Biology

And then a Plank in Reason, broke. You trusted reason to hold. It has always stood outside the wreckage and taken notes. This time it snaps. Down, and down, a world at every plunge. Because the person who regulated you was also how the world stayed legible, and with them gone you reach out and meet nothing, and the nothing spreads until the world itself comes unstrung, senseless, the plank gone and no floor of meaning under it.

Plath has the metallic taste in her mouth, the tin a doorway to an industrial kill-floor: burnt nerves, cut throats, the assembly-line, the green poison, the quiet ride to the sea that’s really a ride to the grave. Grief has run out of places to be, so it comes up through the body as machinery, noiseless and without an off switch.

When a rat loses its partner oxytocin goes down, stress hormones go up, and its tiny heart beats too fast in its tiny dark chest. A whole limbic system the size of a lentil, unraveling when you take its one animal away. Scale that up. Give it a poet’s mind, big enough to know what it lost, language enough to write it down, and you have Dickinson on the plank and Plath’s burnt nerves — the same mammal-grade wiring, the same hormones cratering, only now there’s a whole literate consciousness bolted on top with nothing to do but describe the wreck in real time. That’s the upgrade evolution sold us. A better seat for the same free-fall. The one who kept your rhythm leaves, and your body comes apart in the specific: hormone by hormone, plank by plank, the mouth gone to metal.

VII. The Starving Body

What is loneliness if not unimaginable

Light and measured in lumens—

An electric bill which must be paid,

A taxi cab floating across three lanes

With its lamp lit, gold in wanting.

At 2 a.m. everyone in New York City

is empty and asking for someone.

— Natalie Diaz, from “Manhattan Is a Lenape Word,” Postcolonial Love Poem

Chronic social isolation increases the activation of the hypothalamic pituitary adrenocortical axis, and these effects are more dependent on the disruption of a social bond between a significant pair than objective isolation per se.

— Cacioppo et al., 2015, Annual Review of Psychology

Read the research result twice, slowly, because it’s saying the whole thing under its breath. The stress system doesn’t fire hardest at being alone. A week in a cabin and you come back rested. It fires at the disruption of a social bond between a significant pair. The specific missing person, not simply solitude. This person, whose absence the body keeps grinding like a raw nerve: the open loop. And Diaz hands that alarm a city, a skyline of grief, every lit window at two in the morning a person emptied out and asking, the loneliness gone so wide it turns to light, so total you could bill it by the lumen, a taxi crossing three empty lanes with its lamp on, gold and wanting. I’ll admit my own hand here. I’m one of the lit windows. I work alone in a room, I prefer it, I’d choose it again tomorrow, and some part of me I never consulted is filing a report anyway, my open loop reaching out over a table set for one and finding, most mornings, no second heart to keep its time against. We built a world where the loop can stay open for days. The body was built for another thing. It’s still keeping time, in the dark, for a heart that isn’t there.

WORKS CITED

Scientific sources

Blumenthal SA, Young LJ. The neurobiology of love and pair bonding from human and animal perspectives. Biology (Basel). 2023;12(6):844. doi:10.3390/biology12060844.

Cacioppo JT, Cacioppo S, Capitanio JP, Cole SW. The neuroendocrinology of social isolation. Annu Rev Psychol. 2015;66:733-767. doi:10.1146/annurev-psych-010814-015240.

Carter CS. Oxytocin and love: myths, metaphors and mysteries. Compr Psychoneuroendocrinol. 2022;9:100107. doi:10.1016/j.cpnec.2021.100107.

Emanuel N, Harrington E, Pallais A. Home alone: remote work, isolation, and mental health. Science. 2026;392(6802):eaec7671. doi:10.1126/science.aec7671.

Fisher HE, Brown LL, Aron A, Strong G, Mashek D. Reward, addiction, and emotion regulation systems associated with rejection in love. J Neurophysiol. 2010;104(1):51-60. doi:10.1152/jn.00784.2009.

Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D. Loneliness and social isolation as risk factors for mortality: a meta-analytic review. Perspect Psychol Sci. 2015;10(2):227-237. doi:10.1177/1745691614568352.

Meyer ML, Williams KD, Eisenberger NI. Why social pain can live on: different neural mechanisms are associated with reliving social and physical pain. PLoS One. 2015;10(6):e0128294. doi:10.1371/journal.pone.0128294.

Literary sources

Diaz N. Manhattan is a Lenape word. In: Postcolonial Love Poem. Minneapolis, MN: Graywolf Press; 2020.

Dickinson E. I felt a Funeral, in my Brain (#280). In: Johnson TH, ed. The Complete Poems of Emily Dickinson. Boston, MA: Little, Brown; 1960.

Lewis T, Amini F, Lannon R. A General Theory of Love. New York, NY: Random House; 2000.

Nao VK. The Vanishing Point of Desire. 3rd Edition. Iowa City, IA. Per Second Press; 2015.

Paz O. Sunstone / Piedra de Sol. In Weinberger E, trans. The Collected Poems of Octavio Paz 1957-1987. New York, NY: New Directions; 1991.

Plath S. Waking in winter. In: Hughes T, ed. The Collected Poems. New York, NY: Harper & Row; 1981.

Rich A. Twenty-one love poems (IX). In: The Dream of a Common Language: Poems 1974-1977. New York, NY: W.W. Norton; 1978.

Sappho. Fragment 39. In: Barnard M, trans. Sappho: A New Translation. Berkeley, CA: University of California Press; 1958.