Body Quirks
Quirky questions about our bodies pop up in conversation everyday…or just in our own curious minds.
In this issue of Search + Discover, University of Minnesota faculty and staff explore:
Plus, you can explore further reading and related links.
Why do songs get stuck in you heads and it’s almost impossible to get them out?
The existence of “earworms”—a perceptual phenomenon, not an actual creature—has been acknowledged for many years. In fact, in 1876, Mark Twain wrote A Literary Nightmare, in which he describes an annoying “jingling rhyme” he could not get out of his head. According to research about 98 percent of us have been afflicted by an earworm at one time or another.
The cause of earworms is not clearly understood. One explanation is that the neural circuits representing a song get stuck in “playback mode,” and a snippet of the song plays over and over again in our head. Simple, repetitive songs are the most likely candidates to embed as an earworm. In addition, musicians are more likely to have the experience than nonmusicians; women more likely than men; and individuals with obsessive-compulsive disorder are more likely than others to report the experience.
Individuals have proposed a number of possible methods to free themselves of the insidious earworm. One method, a “replacement strategy,” suggests that finding another song to interest the mind will provide relief. As often as not, however, the outcome is simply displacing the original earworm with an equally annoying replacement. A second method, a “completion strategy,” is built upon the premise that if you listen through a piece in its entirety, the earworm will sometimes go away. Neither method, however, provides a failsafe method for getting rid of a persistent earworm, so you may have to live with the malady.
Following are some of the most commonly reported earworm songs:
(NOTE: Be warned—should you read this list of songs, one of them is bound to be stuck in your head for the next few hours. With that in mind, proceed if you dare.)
- “YMCA” by the Village People
- “The Lion Sleeps Tonight” by The Tokens
- “Macarena” by Los Del Rio
- “Who Let the Dogs Out” by Baha Men
- “We Will Rock You” by Queen
- “Whoomp, There It Is” by Tag Team
- “It’s a Small World After All” heard at Disney parks
- Theme from “Mission Impossible”
—Scott D. Lipscomb, associate professor and division head, Music Education and Music Therapy, School of Music, Twin cities campus
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Why do men have nipples (and women, orgasms, for that matter)?
S.J. Gould’s essay “Male nipples and clitoral ripples,” and E.A. Lloyd’s book The Case of the Female Orgasm: Bias in the Science of Evolution explain it all. It’s a product of developmental bias: Men have nipples because women need them, and both sexes have pretty much the same developmental/genetic circuitry all the way down. A mutation that knocked out male nipples would most likely knock out female nipples as well, and that would be highly deleterious. So expression of the nipple in males is maintained because it must be preserved in the female.
Here is a quote from Gould:
“Male mammals have nipples because females need them—and the embryonic pathway to their development builds precursors in all mammalian fetuses, enlarging the breasts later in females but leaving them small (and without evident function) in males.”
Both of the works above also discuss the complementary question: Why do women have orgasms? It’s the same answer. The capability is maintained in the female because it must be preserved in the male. (In case you’re thinking that’s sexist, Lloyd’s first name is Elisabeth, and the point of her book is that past research that tries to assign a functional role to the female orgasm that is comparable to the male’s is a product of a masculine bias in science—it’s a very good book, and one of the clearest expositions of evolutionary logic that I’ve run across.)
—P.Z. Myers, biology professor, Morris campus
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Can someone really die from a broken heart?
In a word, maybe. Emotions can profoundly affect our physical state, as anyone who’s lost his or her appetite after getting bad news can attest. Just as excitement can make one’s heart race, so the flip side—depression and grief—can influence how the cardiovascular system behaves.
Several studies have turned up correlations between depression and the incidence of cardiovascular disease and death. For example, a study of middle-aged and older widowers found that in the first six months of widowhood, they died at a rate 40 percent higher than expected for married men of their age, largely from heart disease. In general, death rates for both men and women are lower if they are married rather than divorced. Even in the absence of bereavement, depression and a lack of social support are risk factors for death, particularly from heart ailments.
“Human loneliness now ranks among the most important contributors to premature death in America,” said psychophysiology researcher James Lynch in a recent talk at the University.
People with more social support tend to live longer after heart attacks, and people with pets are more likely to be alive a year after such an event. The presence of pets in nursing homes has been linked to improved patient well-being.
The mechanisms by which loneliness and depression work their mischief are still under investigation, but changes in blood pressure and heart rate seem to be at least part of the picture. In experiments with dogs, the hearts of dogs that expect to receive an electric shock beat fast, but having a person in the room with the dog lowers the heart rate. If the person also pets the dog, the rate drops to near-normal levels.
Although talking is a widely used form of therapy, people who talk in rapid, explosive speech patterns can actually be stressing and weakening coronary arteries, Lynch says. Talking about stressful topics can cause a big rise in diastolic blood pressure. Better to get a massage; it can lower blood pressure by up to 30 percent. And hold on to your friends.
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What causes an ‘ice cream headache’?
Headaches have many causes. They are one of the most common health complaints, both for children and for adults.
The so-called “ice cream headache” isn’t one of the biggest public health problems, but it is certainly common. It’s caused by eating or drinking something very cold, not necessarily ice cream. Experts at the University’s Boynton Health Service advise that to prevent ice cream headaches, warm the cold food or beverage for a few seconds in the front of your mouth. Eating or drinking more slowly will also help.
The exact cause is a matter of some debate. According to some researchers, the pain seems to originate when the cold stimulates the trigeminal nerve, which carries sensory information from the face, teeth, and tongue to the brain. The brain then interprets the cold as pain. The soft palate area of the mouth seems particularly sensitive to cold.
Some researchers think people who suffer from migraine headaches are more susceptible to ice cream headaches; others think the opposite. Eating ice cream can, in some instances, trigger a migraine attack. But simply getting an ice cream headache, which children sometimes call “brain freeze,” from cold food should not be a cause for concern.
Ice cream headaches usually disappear within a matter of seconds, though they can, on rare occasions, last a few minutes. No one need give up eating cold treats for fear of them. For more on all kinds of headaches, visit the Boynton Health Service Web page.
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Why do we twitch when we’re falling asleep?
Twitching of the limbs and facial muscles while falling asleep, if not excessive, is a normal transitional wake-sleep phenomenon. Transitional states of sleep and wakefulness not uncommonly release brief and usually inconsequential motor and sensory phenomena, such as twitching, jerking (a prominent or nearly full body jerk is called a “sleep start” and is usually a normal variant), head or body rocking, tooth grinding (bruxism), making sounds, sleeptalking, hearing sounds/voices, loud bangs, or even explosions, or seeing things that are not there, which can be very unsettling. Also, brief moments of paralysis can take place during entry into sleep or arousal from sleep.
Any of the just-described events, when too frequent and/or intense, then becomes a clinical symptom that needs to be evaluated and perhaps treated. The brain is programmed to initiate state transitions and so with billions of neurons shifting gears during a change of state, it is not surprising that all sorts of little (or at times big) misfirings in the neurons are taking place, resulting in these motor and sensory events. It can take a little while for the brain to settle into its new state.
I recently wrote a book that considers this question while also describing the ever-growing set of abnormal behavioral and experiential phenomena emerging from sleep (the parasomnias) and their interactions with common sleep disorders. The book is called Sleep: The Mysteries, The Problems, and The Solutions (Penguin/Avery Press). Also, I produced and participated in a documentary film, along with eight of my patients, called “Sleep Runners: The Stories Behind Everyday Parasomnias.”
—Carlos H. Schenck, Minnesota Regional Sleep Disorders Center, Department of Psychiatry, Twin Cities campus
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Why do we cry when we’re sad?
Human beings are the only animals who have evolved the ability to cry tears when they are sad or experience other forms of emotional stress. Crying is a natural adaptive response to emotional stress. Studies we have conducted in adult men and women show that people usually feel better after crying—less sad, less angry, etc. Thus, as Charles Darwin suggested more than 100 years ago, crying helps to relieve suffering. I have further suggested that we may feel better after crying because we are literally “crying it out.” Chemicals that build up during emotional stress may be removed in our tears when we cry. This is, however, only an unproven theory. Because unalleviated stress can increase our risk for heart attack and damage certain areas of our brain, the human ability to cry has survival value.
—William H. Frey II, director, Regions Alzheimer’s Research Center, and professor of pharmaceutics, neurology and neuroscience, Twin cities campus
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Last modified on June 13, 2008