On a rainy night two years ago, the rapper Dessa pulled over on the side of the road to take a call. The name of a man she had dated on and off for years flashed across caller ID; they weren’t dating any longer, but the sight of his name still inspired a “full bloom of feeling” in her chest.

She picked up. He had called about nothing important.

After hanging up, she felt deflated, then furious with herself. “I asked myself, what exactly had you been hoping would happen?” she says. “Were you expecting him to be parked behind you with a bouquet?” Such an action would make no sense, and she knew it. “Why can’t you stop hoping? What would it take for you to fucking let go?”

A writer as well as a musician — her essay collection My Own Devices: True Stories From the Road on Music, Science, and Senseless Love will be published this fall — Dessa had long turned to philosophers, writers, and poets like Bertrand Russell, David Foster Wallace, Mary Oliver for answers to her questions about loss, love, and connection. But that night crystallized her inability to let go and, perhaps, the need for a different type of answer.

A few months later, she came across the work of the well-known anthropologist and love researcher Helen Fisher. Love, like so much else, is not just social and psychological but also biological. Scientists like Fisher have used brain scans to find the so-called neural correlates of love or the places in the brain where the love “lives.” The experiment that followed would mark her foray into science and influence her new album Chime, which comes out today. She began a study of one, to see if brain imaging and a technique called neurofeedback could help her, finally, fall out of love.

Dessa is tall — six-foot-two in her highest kicks, she raps in one of her new songs — with shoulder-length hair bleached blond. After a lifetime in Minnesota, she moved to New York City part-time in 2016. The move gave her the time and space to forge a new routine after the breakup, she says, plus she’d always had a crush on New York as a literary capital, and she wanted to be part of that world.

Also a member of the indie hip-hop collective Doomtree, she now has four solo albums and a Hamilton mixtape song under her belt. She’s written heartbreaking songs about relationships before, and she has people approach her with their own stories of lost love they couldn’t shake after five, 10, or even 30 years.

“Jesus, how many people are quietly, tortuously, fixated on a love they can’t have?” she says when I sat down to interview her the day after Valentine’s Day. It’s a question she asked herself a lot in the lead-up to Chime, which influenced the single “Good Grief.” While a few years of mourning her ex made sense, “at 12 [years], I don’t perceive that I’m growing and learning. I’m stuck, and I’m not helping him and he’s not helping me.”

Dessa’s turn toward neuroscience for answers is part of a long history of science shaping music and vice versa. The ancient Greeks believed that music and math and astronomy were all intertwined, says Peter Pesic, a pianist, scholar, and author of Music and the Making of Modern Science. Astronomer Johannes Kepler’s interest in music influenced how he thought about our Universe. For Isaac Newton, music showed up in the way he treated color. He created seven colors in the spectrum — ROYGBIV — because he wanted it to match the number of notes in a musical scale. “Music, like octaves and half-notes, is ratios made audible,” says Pesic. “Music was the first place where people got the idea that numbers weren’t just physical things in the world, and that is the origin of modern science.”

Musicians have also drawn from science (though perhaps the most famous example — Gustav Holst’s “Planets” orchestral suite — was actually about astrology and not astronomy). Kate Bush sang a song about “Pi,” John Adams wrote an opera about the Manhattan Project, and in 2011, Björk created a concept album called Biophilia about music and science, complete with songs like “Virus” and “Cosmogony.”

Chime, which Dessa helped produce, is not an album about science and technology, but about science as another way to investigate experience. There are no songs about brain waves or explaining how electrodes work. Everyone I spoke to emphasized that Dessa’s case study is not published research and not intended as an official scientific study, but rather a lens for examining her questions about love and loss through art.

In order to get rid of something, a good first step is to figure out where it is. Dessa went to the Center for Magnetic Resonance Research at the University of Minnesota to figure out where her love was — in a neurological sense. Cheryl Olman, a professor and brain imaging expert at the university, agreed to wheel Dessa inside a huge machine that uses magnetic fields to measure blood flow in different parts of the brain and show them in pictures. (The technique is called functional magnetic resonance imaging, or fMRI.) Emotion is difficult to pinpoint because there is no region or chemical solely responsible for it, but if one brain region shows more blood flow when someone experiences a given emotion, that region likely plays a role in regulating said emotion.

The brain is always working, so certain parts will always light up during an fMRI scan. The trick, then, was to figure out what Dessa’s brain scan looked like when she thought about her ex, and, though a process of elimination, what made it different. Olman took images of Dessa’s brain while showing her pictures of her ex (“dude A”) and then pictures of a platonic male friend (“dude B”). By comparing the two, the theory went, they could subtract the areas of activity generated by the “dude B” image from the “dude A” image to see which part of the brain was still active — the place the love and obsession remained.

Dessa’s hands are covered in silver rings and jewelry that she doesn’t take off even when she sleeps and showers, she tells me, holding her hands in front of her, fingers splayed. None of that could go into the fMRI machine, where she laid on her back feeling dizzy as the first image of her ex flashed above her. He was looking directly at the photographer in the picture, and so it looked like he was looking directly at her. The study was single-blind, meaning that while Dessa obviously knew which man was which, Olman didn’t. “But, actually, it was quite obvious,” says Olman. “Her brain was clearly more into dude A.”

The results came in while Dessa was sitting in a coffee shop in the Upper East Side. The brain regions that activated when she looked at her ex were the anterior cingulate, the ventral tegmental area (VTA), and the caudate. These regions are generally involved with not just emotion, but reward, motivation, and goal-seeking, according to Olman.

Dessa started to tear up as she looked at the fMRI images. Of course she knew she was in love; that was what had inspired the entire project. “But to see an image that represented that feeling, it’s almost like this love that had been making me so crazy for so long —someone else got to see it, too,” she says. The scan provided something quantitative and empirical, outside her subjective experience. “It tripped me out pretty hard to have a postcard of this feeling,” she said, “something I could touch.” (Later, the Center for Magnetic Resonance Research 3D-printed the caudate. Dessa also commissioned a huge disco ball version that hung from the ceiling during a presentation.)

“I liked the idea of a universe in which it feels like we’re all actively plotting our courses, but really, your environment is such that it’s predetermined.”

Dessa had found the location of her love. The next question was what she would — or could — do with this information. “I thought, do I even have the ability to choose to stop loving this man?” she asks. Or did she even want to?

“Half of You,” one of the pop songs on Chime, asks that question. Over a synth-pop beat, she asks: “What if I could cure me of you? / Am I so sure which pill I’d choose?” Perhaps, she muses, she’d be happier with “half of you” than in “clean but empty rooms.”

But after so many years, it was time for a change. You could think about a brain scan like a playlist of music, one where the activated regions, or brain waves, represent the songs and moods you play over and over. Dessa wanted to stop playing the same song — the one in which she was perpetually heartbroken.

Tampa-based mental health clinician Penijean Gracefire had often used Dessa’s music — songs like “Alibi,” “Dixon’s Girl,” and “Into the Spin” — in her work with domestic violence victims, so when she saw Dessa ask on Twitter if any followers had access to fMRI or electroencephalography (EEG), Gracefire immediately responded.

Gracefire uses a method called neurofeedback with patients to help alleviate conditions like anxiety and depression. The first step is using an EEG to read brain waves and help patients visualize what their brain is doing. Electrodes attached to specific points on the outside of their heads record the electricity of neurons so patients can see their brain activity on a screen in real time and understand its patterns.

If brain scans function like a visual playlist, explains Gracefire, the specific shape of these waves tell you whether your brain is always playing the blues station or a hyper-neurotic dubstep channel. And because brains love patterns, once you train it to spend a lot of time in one “station” — such as thinking about your ex all the time — it gets rigid and is less able to play the other songs. Her goal is to make the brain more flexible and play more than just songs in minor keys. To get rid of something like obsessive love, where the brain is stuck in a loop, you have to train the brain to work differently.

Gracefire and Dessa met up at Dessa’s father’s house in Florida. There, Gracefire took EEG readings of the rapper’s brain and compared them to existing studies showing the typical range of brain activity involved in the cognitive and emotional parts of romantic love. It was clear that Dessa’s readings — the shape of her brain waves — were outside the typical range.

Next, Gracefire developed a training program. Over a couple weeks, the two had nine, 30-minute neurofeedback sessions. Each time, Gracefire attached electrodes to Dessa’s head and played a specific pattern of harp-like tones while they watched her brain waves take shape on-screen.

Our brains are trained to notice what’s different, and a high-pitched sound will grab its attention, says Gracefire. Brains like hearing high-pitched sounds, and so, when Dessa’s brain pattern matched the desired shape, a high-pitched sound would play as a reward. Her brain would want to hear it again and would create another wave in the shape they wanted, and so on. It was a passive program; Dessa didn’t need to think about her ex. She just needed to sit there, watch the squiggles on the screen, and let her brain process and learn.

Afterward, Dessa jokes, she decided she doesn’t believe in free will anymore. Her love for her ex had not felt like free will, and sitting with electrodes stuck to her head had been a passive experience, but it had made something change. That tension is present in the first line of a soft, piano and violin-backed song on Chime called “Velodrome.” “I don’t believe my will’s quite free / I’m half machine, at least half steam.”

“I felt like I’d been let through so many secret doors.”

“I liked the idea of a universe in which it feels like we’re all actively plotting our courses, but really, your environment is such that it’s predetermined,” Dessa says. We intuitively feel free, but feeling is not reality, and we’re influenced by so many things we can’t fully see or understand, like our brains. Dessa had not been able to fall out of love through sheer will alone. Playing some high notes for her brain didn’t quite feel like will either, but it had changed the machinery.

After the experiment, EEG results from Gracefire and another brain scan by Olman both showed physiological differences. But, as Olman says, “The value is not in the scan; the value is in whether she felt differently.”

The emotions were still there — she hadn’t been lobotomized — but the obsessive feelings that had haunted her for so many years had lost their power. “I knew our history, still, and respect and regard and attraction and regret and jealousy — all of those were still there,” Dessa says. “But it just felt like some of the absolute compulsion and total fixation had been leveled down, and the immediacy of all of those crazy-making feelings had dissipated. I just felt chiller.”

When her father asked her how she felt after the experiment, she tried to hedge about the importance of not reading too much into one case study — how you can’t extrapolate from one person, and, maybe, if they repeated the experiment they might have completely different results. But her father wasn’t interested in the technical details.

He simply said: “You seem different.”

Of course, an album is a playlist, too. Dessa’s brain became more flexible from the neurofeedback sessions, and in Chime, her music also shows more diversity in style. There are aggressive bangers, “rap noir,” a piece about gender politics on how “a woman on her own must be from out of town,” a ballad called “Boy Crazy,” a pop song.

One song references the Catholic philosopher Thomas Aquinas (though not too much expository stuff, she jokes, because “I don’t like when it’s like ‘I’m gonna tell you in rhyming form exactly how this thesis works.’ Let’s keep it chill.”). Another talks about heart contractions. Other themes include light and heat, secrets that aren’t being kept, and the body as a machine, as physical material that yet that create so much experience.

“To be able to 3D-print the structure of my brain responsible for these feelings for the past 10 years and hold it in my hand” — Dessa holds her left hand up in front of her, palm out — ”well, what a different kind of investigation to feel like than any I’d been able to do before,” she says. “I felt like I’d been let through so many secret doors to understand these feelings from a different perspective.”

More information about Dessa’s tour dates is available on her Facebook, Instagram, and Twitter.