Those delicious chills you get as your favorite piece of music reaches its climax? They’re the result of a glorious spike of dopamine in your brain–that’s the same neurotransmitter that’s involved in reward, motivation, and addiction.
In a nifty series of experiments published in Nature Neuroscience, researchers determined that music provokes floods of dopamine in music lovers. Study coauthor Valorie Salimpoor notes that dopamine has long been known to play a role in more physical activities like taking drugs and having sex, but this research highlights its role in other aspects of our lives.
“It is amazing that we can release dopamine in anticipation of something abstract, complex and not concrete,” Salimpoor said. “This is the first study to show that dopamine can be released in response to an aesthetic stimulus.” [Discovery News]
From Ed Yong:
In an Israeli laboratory, Shani Gelstein is harvesting a woman’s tears. The volunteer is watching the end of the boxing film The Champ. As she weeps, she holds a vial under her eyes to capture the fresh drops. This might seem ghoulish, but Gelstein has used the collected tears to understand why people cry during emotional times. She thinks they’re a chemical signal.
Gelstein used several different techniques to show that the smell of a woman’s emotional tears could reduce a man’s sexual arousal. The men never actually saw anyone cry, and they didn’t know about what they were smelling. Even so, their sniffs reduced their testosterone levels and they lowered the activity in parts of their brain involved in sexual desire.
The small study had men smell both women’s tears and saline that had dripped down women’s cheeks, and measured the men’s reactions. The fascinating (if preliminary) results suggest new possible reasons why we cry at emotional times–read the rest of the story at Not Exactly Rocket Science.
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Image: Science / AAAS
You’ve probably heard oxytocin referred to as the “love hormone,” but a new study in the Proceedings of the National Academy of Sciences reminds us that there’s much more to it than that. Jennifer Bartz and colleagues treated men either with nasal sprays that included oxytocin or placebo sprays that didn’t, with peculiar results.
Before all of this, the men completed a series of widely used questionnaires to measure the state of their social ties. The questions assessed the nature of their bonds with their families and friends, how sensitive they are to rejection, how comfortable they are at being close to other people, how much they desire that closeness, and more. Shortly after using both sprays, the recruits also answered questions about their mother’s parenting style.
Bartz found that when she averaged out the volunteers’ results, the sniffs of oxytocin hadn’t seemed to colour their memories of their mothers. But things changed when she looked at them individually. Those who felt more anxious about their relationships took a dimmer view of their mother’s parenting styles when they sniffed oxytocin, compared to the placebo. Those who were more secure in their relationships reacted in the opposite way – they remembered mum as being closer and more caring when they took the oxytocin.
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Staring at your beloved’s face really can take the pain away and make everything better. A small but intriguing study has found that college students who looked at pictures of their beloveds felt less pain than others.
The study, published in PLoS One, was a collaboration between the pain researcher Sean Mackey and the love researcher Arthur Aron, who wondered how their fields might overlap in the brain. First they put out the call for volunteers in the early, passionate stages of a relationship.
The authors recruited 15 Stanford undergrads who were “wildly, recklessly in love,” said Mackey, adding that the recruitment process took “only days. It was the easiest study I’ve ever recruited for,” he said. “Within hours they were all banging on my door, ‘Study us! Study us!’ When you’re in that kind of love, you want the world to know about it.” [HealthDay News]
At the lab, the 15 volunteers either looked at photos of their beloveds, or at photos of an “equally attractive” acquaintance. In a third variation meant to test the impact of a mental distraction, the volunteers were asked to perform a cognitive task like listing sports that aren’t played with a ball. Then the researchers dialed up the pain, using a heated probe which they pressed against each person’s palm.
Doggie separation anxiety–the whining, scratching, and general misbehaving that happens when some dogs are left home alone–is somehow linked to the dog’s general outlook on life, new research says. Coauthor Emily Blackwell explains that she wondered whether the behavior she’d observed during high school in her own anxiety-prone dog was normal.
“So many people think [separation-related behavior] is just something dogs do.” … They think the dog is angry the owner is leaving, say, and exacting its revenge on the owner’s slippers. [ScienceNOW].
For the study, published in Current Biology, the team investigated the link between this separation anxiety trait and a pessimistic attitude. To test pessimism, 24 dogs were trained to associate a full food bowl with one side of a room and an empty bowl with the opposite side.
The dogs learn quickly “if it’s on one side, to race over and nearly knock over the screen to get it,” says Blackwell. “If it’s on the other side, they look around and quite often give us a big sigh.” Some dogs amble over to check out the empty bowl; others just lie down. [ScienceNOW]
If there’s a certain smell or sound that instantly brings back traumatic memories, it could be because those memories are stored—at least in part—in brain regions associated with the input of your senses, according to a study this week in Science.
Neuroscientist Benedetto Sacchetti went looking in rat brains for the neural connections between the senses and intense memories.
Each sense, including sound, smell and vision, has a primary and a secondary sensory cortex area in the brain. The primary cortex sends sensory information to the secondary cortex, which then connects to emotional and memory areas of the brain [Science News].
Recreational drug users call it “Special K.” Large, frequent doses of the anesthetic ketamine can give users vivid hallucinations, but a recently published study hints that the drug may have a medicinal use: temporarily treating depression brought on by bipolar disorder.
The small, proof-of-concept study appears in the journal Archives of General Psychiatry. National Institutes of Health researchers randomly gave 18 depressed patients ketamine or a placebo on two different days, two weeks apart. They used a much smaller dose of the drug than the amount used for recreation or anesthesia, but within 40 minutes 71 percent of the patients who received ketamine showed a significant improvement in mood, which lasted for three days, as measured using a psychiatric depression rating scale.
The quick response time is unusual for the drugs typically used to treat bipolar disorder’s depression, such as lithium or antidepressants like Prozac, and many of the study’s patients had failed to respond to other treatments. On average, the study participants had tried seven antidepressants and 55 percent of participants had failed to respond positively to the extreme measures of electroconvulsive therapy (ECT)–seizures brought on by electrical current. Ketamine’s apparent success may have to do with the neurotransmitter, glutamate:
It’s the essence of instinct: If you take a lab mouse who has never caught a glimpse of a cat and waft a little eau de feline towards it, the mouse will freeze in fear, and will then back away from the source of the odor. Now researchers have pinned down the chemical signals the mice are reacting to–and have shown in the process a fascinating new form of inter-species communication.
Mice have a specialized organ in their noses that picks up chemical signals, called the vomeronasal organ, which helps them detect pheromones emitted by other mice. These mice pheromones have a direct effect on behavior–most obviously in the realms of mating and fighting. In this new study, published in the journal Cell, neurobiologist Lisa Stowers decided to investigate whether the vomeronasal organ was capable of picking up signals from other species as well.
Shakespeare’s Lady Macbeth may have had the right idea when she scrubbed her hands following the murder of King Duncan. An odd new study suggests that hand washing may help people deal with the emotional consequences of decisions–and not just big decisions, like whether or not to participate in regicide, but also minor calls, like which free CD to take home.
[Psychology researcher Spike W. S. Lee] and a colleague named Norbert Schwarz decided to test hand washing’s effect on one kind of bad feeling: the lingering tension we feel after being forced to choose between two attractive options, because picking one option makes us feel that we’ve lost the other. Psychologists know that people usually try to soothe this inner conflict by later exaggerating the positive aspects of their choice. “In other words, after they make the choice, they will like the chosen option more than before the choice,” Lee explains [NPR].
For the study, published in Science, the researchers told students they were evaluating products for a consumer survey. The students first ranked 10 CDs in order of preference, and were then told they could take home either their fifth- or sixth-ranked CD as a token of appreciation. After they made their choices, they were told it was time to evaluate a liquid soap–but some students washed with the soap, while others only looked at its packaging. Finally, the students were asked to rank the same set of CDs again.
Scientists have long suspected that a link exists between mood and chocolate, as studies (done primarily with women) have suggested that eating a chocolate bar temporarily banished the blues. Now a study has brought new complexity to the issue with its finding that depressed people consume larger amounts of chocolate. But researchers are no closer to figuring out which factor is the cause and which is the effect: Do glum people reach for a Hershey bar to lift their spirits, or is the chocolate actually bringing them down?
For this study, researchers at the University of California studied 931 men and women who weren’t on antidepressants and quizzed them on their chocolate-chomping habits. Then, using a standard screening survey, they assessed the volunteers for symptoms of depression. The scientists found that those who were the most blue consumed the most chocolate.