Why scientists are battling over pleasure
News and notes about science
A battle over pleasure has broken out. On Twitter and in the pages of scientific journals, psychologists, neurologists and neuroscientists are forging alliances over the question of whether pleasure we get from art is somehow different from the pleasure we get from candy, sex or drugs.
The debate was ignited by an opinion piece titled “Pleasure Junkies All Around!” published last year in the journal Proceedings of the Royal Society B. In it, Julia F. Christensen, a neuroscientist at the Warburg Institute at the University of London who studies people’s responses to dance choreography, argued that many of us have been turned into “mindless pleasure junkies, handing over our free will for the next dopamine shoot” provided by social media, pornography and sugar. She offered up an unconventional solution: art, which she says engages us in ways these other pleasures do not and can “help overwrite the detrimental effects of dysfunctional urges and craving.”
The paper struck a nerve with some of her fellow art and pleasure researchers, who published a rebuttal last month in the same journal. The idea that the way that art engages the brain is somehow special has been around for far too long and it is time to kill it off once and for all, they insist.
“Christensen has recently argued that the pleasure induced by art is different to the pleasure induced by food, sex, sports, or drugs,” wrote Marcos Nadal, a psychologist at the University of the Balearic Islands, and Martin Skov, a neuroscientist at the Danish Research Centre for Magnetic Resonance. “Her argument, however, is contradicted by plenty of evidence showing that the pleasure from art is no different in genesis and function to the pleasure induced by food, drugs, and sex.”
Their comment spurred others to rally to Christensen’s defense.
“Do you have an alternate idea?” Dr. Anjan Chatterjee wrote on Twitter. “Do you think the pleasure is the same as a dab of sugar on your tongue?”
(Chatterjee is a neurologist at the Perelman School of Medicine at the University of Pennsylvania who wrote “The Aesthetic Brain: How We Evolved to Desire Beauty and Enjoy Art.”)
The arguments over Christensen’s paper pointed to disputes within the emerging field of neuroaesthetics, or the study of the neural processes underlying our appreciation and the production of beautiful objects and artworks:
On Team 1 you’ll find the argument that the experience of pleasure from art is neurobiologically identical to the experience of pleasure from candy or sex.
Team 2 believes that both making and appreciating art can offer unique neurobiological rewards.
Team 3 asks, “Who knows?!” (“Who cares?!” seems to be a subset of this group.)
Given that pleasure is known to be a powerful motivator of human behavior, it’s a dispute with implications far beyond art — at least according to Team 1 and Team 2.
“It’s starting to get really hot,” Nadal said of the debate. (In case you were wondering — he studies architectural lines because they are everywhere, affecting us in ways most of us have never considered, and they make “for good laboratory material because they are easy to control.”)
There are some core elements that all sides seem to agree on:
As with wine, how much people enjoy art seems to be affected by contextual cues like price or the reputation of the creator.
Art is difficult but possible to define. (Definitions vary however.)
Across cultures, what people perceive as beautiful is less consistent with artwork than it is with architecture, landscapes and faces. (Faces are the most consistent.)
What researchers do not agree on is whether enjoying a da Vinci engages a different neural process than enjoying a visit to Pornhub or Mcdonald’s.
Nadal, speaking for Team 1, said in an interview that “humans appear to use only one pleasure system to assess how pleasurable or unpleasurable a sensory experience is.” He calls this discovery “one of the most important insights to emerge from the last 15 years of neuroscience,” and believes it shows that while enjoying Cheez-its or a sculpture may feel different, in our brains they are processed the same way.
Others who study pleasure are not convinced.
“Talking in terms of shared neural systems is foolish,” said Paul Bloom, a psychology professor at Yale University and author of the book “How Pleasure Works: The New Science of Why We Like What We Like.” He thinks that “art scratches all kinds of itches.” While watching “The Sopranos” or parallel parking a car are all done by the brain, he says that doesn’t mean they are the same.
Christensen, who studied dance before she became a neuroscientist, said she was not disputing that a single reward system processed all pleasures. But that does not eliminate the possibility that the arts also activate additional neural systems “related to memory processes, sense of self and reasoning that add something more to this pleasure.” This “high-level pleasure” requires more scientific investigation. But given that we spend our lives chasing pleasures, she argues, why not try to better understand one of the few that “do not induce states of craving without fulfillment,” or cause health problems and instead make “you think and experience things differently.”
All of this may lead you to ask: If pleasures are so similar, why don’t people ever orgasm from pleasure associated with food or art? Actually some do. According to Debra Herbenick, director of the Center for Sexual Health Promotion at the Indiana University Bloomington’s School of Public Health, eating a ripe tomato or reading nonerotic prose has been reported to provoke an orgasm. So, too, has walking barefoot on wood floors and doing pullups.
She cannot yet say why, which lends support to the broader notion that “there is really so much we as scientists still don’t understand about pleasure.”
— Heather Murphy
Nuts may be good for the heart but are hardly a miracle food
There is considerable research showing that nuts, with their high levels of unsaturated fatty acids, fiber and minerals, may help reduce the risk for cardiovascular disease. But a large Swedish analysis published in Heart has found that the benefits are limited and depend largely on other healthy behaviors.
Researchers followed 61,364 adults for up to 17 years. They had all completed questionnaires on diet, lifestyle and other risk factors for chronic disease.
Nut consumption was associated with lowered risk for heart attack, heart failure, stroke and the irregular rapid heartbeat called atrial fibrillation, or A-fib. But people who routinely consumed nuts were on average younger and more highly educated, had lower body mass index, were more likely to be physically active, less likely to smoke, and more likely to eat fruits and vegetables. When the researchers controlled for these factors, nut consumption was associated only with a lower risk for A-fib and had no significant effect on the other cardiovascular diseases.
The lead author, Susanna C. Larsson, an associate professor of epidemiology at the Karolinska Institute, said it was possible that past studies didn’t control for as many factors: “Nuts are a good food, but they may not provide as much benefit as we once thought.”
— Nicholas Bakalar
Ethicists call for more scrutiny of ‘humanchallenge’ trials
Members of a government ethics panel have renewed their criticisms of a controversial study in which volunteers are to be deliberately infected with the Zika virus.
In an article published this month in the journal Science, panel members called for the establishment of ethics committees to review the design of such human-challenge studies, which are sometimes used to test vaccines.
“There is no way to turn back time,” said Seema Shah, a bioethicist at the University of Washington who chaired the panel and is a co-author of the new paper.
“When you’re asking someone to take a risk that won’t benefit them but may benefit others in the future, you need to know two things — that proper protections are in place, and that it’s really going to move the needle.”
With funding from the National Institutes of Health, the investigators plan to inoculate participants with potential vaccines and then to inject them with small doses of the Zika virus to test the vaccines’ effectiveness. The NIH has not yet decided whether the research will proceed.
The scientists leading the trial say it is necessary to prevent a future epidemic. But Shah and other bioethicists convened by the NIH concluded in 2017 that the research had “insufficient value” to justify the risks.
People outside the study, such as sexual partners, might also be infected, the panel said. And Zika infection might have unspecified consequences for participants in the long term.
Human-challenge studies are only conducted at a small number of institutions in the United States. The trials have been used to test vaccines or treatments for dengue, malaria, influenza and norovirus, among other diseases.
Natural Zika outbreaks are becoming too sporadic to test vaccines, so until the next large outbreak, a human-challenge study may be the only way for vaccine developers to proceed.
“This ethics consultation was debilitating for the whole community,” said Dr. Anna Durbin, a research clinician at Johns Hopkins University who collaborated on the study’s design. “It really slammed the door on progress.”
— Emily Baumgaertner
Married people less likely to die from melanoma
Married people are more likely than the unmarried to get timely diagnosis and treatment for malignant skin cancer.
Early detection of melanoma, the deadliest form of skin cancer, is essential to effective treatment.
A study published in JAMA Dermatology used a large cancer registry to catalog tumor stage and marital status in 52,063 patients found to have melanoma. The population, average age 64, was 58.8 percent male. Almost 70 percent were married.
After controlling for age, sex, education level and other factors, the researchers found that 46 percent of married people went to a doctor at the earliest stage of the disease, compared with 43 percent of the never married, 39 percent of the divorced and 32 percent of the widowed. Patients who were never married were 12 percent more likely to present with a later-stage cancer, the divorced 34 percent more likely and the widowed more than twice as likely.
Results were the same for men and women.
“The take-home point is not only that people should get regular skin exams, but also to bring someone with you to the visit,” said the senior author, Dr. Giorgos C. Karakousis, an associate professor of surgery at the University of Pennsylvania.
— Nicholas Bakalar
Concussions may increase Parkinson’s risk
A traumatic brain injury, even a mild concussion, increases the risk for Parkinson’s disease, a new study reports.
Researchers identified all patients in a Veterans Health Administration database who had a brain injury diagnosis — 162,935 men and women — and matched them with the same number of people with similar health and behavioral characteristics but who had not had a brain injury. The study is in Neurology.
Of the brain injury cases, half were mild, involving a blow to the head with some subsequent symptoms but with little or no unconsciousness. The rest were moderate to severe, involving extended unconsciousness or long-term symptoms.
After controlling for age, race, income and many medical and psychiatric diseases, they found that compared with those who had had no TBI, those with a mild TBI had a 56 percent increased risk for Parkinson’s disease; those with moderate to severe TBI had an 83 percent increased risk.
— Nicholas Bakalar