Who says love hurts? Romantic partners alter our perception of pain

By Jesse Bering

 

My mother used to say, “there’s somebody out there for everybody.” It sounds sweet, I know, but when you realize she would say this only in jaw-dropping astonishment at seeing a loving couple out in public in which both partners were, shall we say, aesthetically shortchanged in some eye-catching way, my dearly departed mother somehow doesn’t sound like such a Polyanna anymore. But she got it basically right. When two people are in love, the world whittles away to them alone, and as new research findings suggest, a mere reminder of that other person can make everything seem a little more manageable—even, as it turns out, physical pain.
In a study published this month in Psychological Science, psychology graduate student Sarah Master of the University of California, Los Angeles, and fellow researchers invited 25 couples into their laboratory for a study on pain perception. The females—in this study, anyway—got to be the recipients of the experimentally induced pain stimuli. While the male partner was away in another room having his photographs taken for later use in the study, the woman was instructed to place her arm through an opaque curtain. An experimenter on the other side of the curtain first assessed each woman’s “pain threshold” for thermal stimulation, which produces a sharp, acute, prickling pain sensation within about a tenth of a second.

Once the investigators determined each woman’s subjective pain threshold for moderate discomfort—operationalized as a score of “10” on a pain-rating scale of 0 to 20—they proceeded to the experiment, in which the women were subjected to 84 further pain trials. Ouch! Unbeknownst to the female participants, half of these thermal stimulations were administered at the women’s individually predetermined pain threshold levels, and half were set at 1° C above these moderate discomfort levels. In other words, 42 randomly spaced trials during the course of the experiment involved a degree of pain that exceeded the women’s earlier self-reported tolerance for discomfort. This means that at least half of the trials really would have been more than a little painful under normal, all-else-being-equal, baseline conditions.
As in the assessment trials, the participants were again asked to verbally rate each trial’s “unpleasantness” on a sliding scale. And here’s where the romantic partner comes into the picture. The 84 experimental trials were further divided into seven different conditions of six pain stimulation episodes. That is to say, during each painful trial, the woman was either:
(1) holding the hand of her partner (as he sat behind a curtain)
(2) holding the hand of a male stranger (again, with the man behind a curtain)

(3) holding a squeeze ball
(4) viewing her partner’s photographs—the ones taken earlier—on a computer screen

(5) viewing photographs of a male stranger

(6) viewing photographs of a chair

(7) viewing a fixation crosshair
Curiously, the women reported experiencing a slightly greater reduction in pain while viewing their partners’ photographs than they did even for the partner hand-holding condition (although I should point out that the difference between these two experimental conditions was statistically non-significant). More importantly, pain felt under both of these “partner” conditions was significantly less than for all of the other conditions.

It’s unclear from these findings exactly why viewing a photo of a loved one ameliorates pain—perhaps even more so than actually holding that same person’s hand. Master and her coauthors interpret these data as an example of cognitive priming. Seeing a photo of one’s partner stirs up pleasant mental representations of that person, thoughts that have a measurable palliative effect on pain. Unfortunately, the authors do not speculate as to why physical contact with a loved one pales in comparison to simply viewing that person’s photo. One possibility may be that, when a loved one is physically present, the sufferer can become distressed by the other person’s worrying. A photo of a smiling partner, in contrast, is stripped of those unsettling emotional cues and more easily transports the sufferer to a happier place.

The researchers thus conclude:

The findings suggest that bringing loved ones’ photographs to painful procedures may be beneficial, particularly if those individuals cannot be there. In fact, because loved ones vary in their ability to provide support, photographs may, in some cases, be more effective than in-person support.

Fascinating indeed. I must say, however, that I am a bit skeptical about the generalizing of these findings to all romantic relationships. Unfortunately, the researchers do not tell us about the quality of the relationships in the couples used in the study. But I can certainly imagine some instances where, due a strained marriage or some rankling issue such as infidelity, seeing the face of a loved one could actually intensify pain. What a clever clinical test of relationship dissatisfaction that would be.
I, for one, would largely prefer a photo of my dog beside me during a root canal.
In this column presented by Scientific American Mind magazine, research psychologist Jesse Bering of Queen's University Belfast ponders some of the more obscure aspects of everyday human behavior. Ever wonder why yawning is contagious, why we point with our index fingers instead of our thumbs or whether being breastfed as an infant influences your sexual preferences as an adult? Get a closer look at the latest data as “Bering in Mind” tackles these and other quirky questions about human nature. Sign up for the RSS feed or friend Dr. Bering on Facebook and never miss an installment again. For articles published prior to September 29, 2009, click here: older Bering in Mind columns.
Image ©iStockphoto.com/arsenik

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INHIBIR CIERTA ENZIMA MITIGA PROBLEMAS CEREBRALES CAUSADOS POR EL INSOMNIO

Una investigación dirigida por biólogos y neurocientíficos de la Universidad de Pensilvania ha descubierto una vía molecular en el cerebro que es la causa de las deficiencias cognitivas resultantes de la privación de sueño. Además, el equipo cree que los déficits cognitivos provocados por la privación de sueño, como la incapacidad de concentrarse, aprender o memorizar, se pueden revertir mediante la reducción de la concentración de una enzima específica que se acumula en el hipocampo cerebral.

Se sabe que la privación de sueño puede tener consecuencias cognitivas perniciosas, incluyendo deficiencias en el aprendizaje y la memoria, pero siguen siendo desconocidos en buena parte los mecanismos por los cuales dicha privación afecta al funcionamiento del cerebro. En particular, desarrollar técnicas para revertir el impacto de la privación de sueño en la función cognitiva ha sido todo un reto.

Lo descubierto en el nuevo estudio podría ofrecer una nueva estrategia para tratar las deficiencias en la memoria y en el aprendizaje provocadas por el insomnio.

Ted Abel, investigador principal y profesor de biología en la Escuela de Artes y Ciencias de la Universidad de Pensilvania, ha dirigido el equipo internacional de investigadores que ha descubierto que la privación de sueño en ratones afecta a una vía molecular importante en el hipocampo, región cerebral de la que se sabe que es esencial para la memoria y el aprendizaje.

El estudio ha mostrado que los ratones que experimentaban privación de sueño tenían niveles elevados de la enzima PDE4 y niveles reducidos de la molécula cAMP, siendo ésta última crucial en la formación de nuevas conexiones sinápticas en el hipocampo.

Luego, los investigadores trataron a los ratones con inhibidores de PDE, los cuales actuaron contra los efectos perniciosos inducidos por la privación de sueño en la señalización de cAMP, la plasticidad sináptica y la memoria dependiente del hipocampo. Esta reversión también ayudó a mitigar las deficiencias en las conexiones sinápticas en el hipocampo y, por tanto, contrarrestó algunas de las repercusiones de la privación de sueño sobre la memoria.

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The Moral Call of the Wild A study suggests that spending time in nature changes our values

By P. Wesley Schultz

I love spending time outside. From wild places like the backcountry of the Sierra Nevada mountains, to the mundane nature in my back yard, I find comfort in my natural experiences. These places are restful. Peaceful. They restore my batteries, and help me to focus. And I am not alone in these experiences. People around the world seek out natural experiences. Even when confined to built spaces, we add pets, plants, pictures, and momentos from nature. It is part of who we are, and these experiences in nature help us reflect on what is important in life.

The benefits of spending time in nature have been well-documented. Psychological research has shown that natural experiences help to reduce stress, improve mood, and promote an overall increase in physical and psychological well-being. There is even evidence that hospital patients with a view of nature recover faster than do hospital patients without such a view. This line of research provides clear evidence that people are drawn to nature with good reason. It has restorative properties.

But a recent article by researchers at the University of Rochester shows that experiences with nature can affect more than our mood. In a series of studies, Netta Weinstein, Andrew Przybylski, and Richard Ryan, University of Rochester, show that exposure to nature can affect our priorities and alter what we think is important in life. In short, we become less self-focused and more other-focused. Our value priorities shift from personal gain, to a broader focus on community and connection with others.

To demonstrate this effect, they ran a series of studies. In their first study, the researchers randomly assigned individuals to view a slide show that either depicted scenes of human-made or natural environments. The slides were matched across a variety of characteristics, to eliminate the possibility that the results were due to things like color, complexity, or brightness of the images. The participants were instructed to try to immerse themselves in the images—to notice the colors and textures and imagine the sounds and smells. After watching the slide show (which took about 8 minutes), the participants completed a series of questions about their life aspirations.

Of particular interest were responses to extrinsic life aspirations , like being financially successful or admired by many people; as contrasted with intrinsic life aspirations , like deep and enduring relationships, or working toward the betterment of society. The results showed that people who watched the nature images scored significantly lower on extrinsic life aspirations, and significantly higher on intrinsic life aspirations. The effect was particularly strong for participants who reported being “immersed” in the images. This basic effect was further explored in three subsequent studies. The later studies showed the same effect for true nature experiences: being in a small room with plants, for example.

These results are part of a growing body of evidence showing the powerful effect of natural experiences. And, for people like me who enjoy spending time in nature, the results are encouraging. However, when viewed within a larger societal context, the results also provide an intriguing perspective on some noted shifts in the values and priorities or Americans over the past 40 years.

People living in the United States are spending much less time outdoors today than ever before. Data from a variety of sources show that on average, Americans are spending less time outdoors today than they did 30 or even 20 years ago. Children tend to spend more time outside than do adults, but that number too is declining. With the growth of Internet, social networking, on-demand programming, and computer games, there is more to keep us inside than there is to draw us out into the natural environment (or at least, it feels that way).
These trends have not gone unnoticed, of course, and there is a growing concern about the “sedentary lifestyle,” and our loss of connectedness with nature. But the results from Weinstein et al. suggest something else—that this reduction in our exposure to the natural world could drive large-scale shifts in societal values. As their results show, experiences with strictly built environments lead to life aspirations that are more self-focused. These results may help explain the increase in aspirations for fame, wealth, power, achievement, and other self-enhancing values in Western society and predict that this trend is likely to continue.
So the next time you feel like you have lost sight of what is important, take a walk outside. Immerse yourself in the experience. Clear your head by listening to the sounds of the birds, the smell of the sage, and the touch of the breeze. These are the experiences that open our mind and help us to realize that we are part of a larger community.

Are you a scientist? Have you recently read a peer-reviewed paper that you want to write about? Then contact Mind Matters co-editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe, where he edits the Sunday Ideas section.

Want to Boost Your Memory? Try Sleeping on It

By ADI NARAYAN Adi Narayan Mon Nov 30, 10:00 am ET

Can't remember where you put your keys? Here's a tip for you: record the sound of your jingling keys and put it into your iPod. Then get someone to play it to you at night, while you are deep asleep. Chances are it'll help you remember.

That's the conclusion of a recent report in the journal Science by neuroscientists at Northwestern University, who carried out a small study, with 12 volunteers, to figure out whether specific sounds played during sleep would boost the memory of information learned while awake. (See the year in health 2009.)

First, the participants were asked to memorize the correct location of 50 images on a computer monitor. The images were shown one at a time, arranged in a random place on the screen - a cat appeared on the bottom left, a gong on the top right and so forth. Each object was shown with a related sound - so subjects heard a meow with the picture of a cat, and a crashing noise coupled with the image of a gong. After studying the 50 images and locations, the participants were asked to take a short nap in a recliner in an adjacent room.

Volunteers for the study weren't hard to find, notes Ken Paller, professor of psychology at Northwestern University and lead author of the paper: "People are happy when they are paid to have a nap."

The volunteers were outfitted with electrode caps - akin to a white shower cap with a jungle of wires sticking out of it - that tracked their brain waves in order to determine their stage of slumber. Using an electroencephalogram (EEG), investigators monitored the sleepers' brain activity, and just when the squiggly lines on the screen showed that participants had entered deep sleep, researchers began playing a series of 25 of the sounds that the individual had heard earlier in the memory game. "[The volume] was a little over a whisper, probably much [quieter] than ... your iPod," says John Rudoy, one of the study's authors and a graduate student at Northwestern. (See the top 10 medical breakthroughs of 2008.)

When the participants woke up about an hour later, they said they hadn't heard a thing. But the test results suggested otherwise. On average, each person did slightly better at remembering the correct locations of the 25 objects whose related sounds had been cued during sleep than those of the other objects. The sounds appeared to have entered the sleeping brain and helped consolidate associated memories.

Many researchers who study sleep and memory were excited by this new study (not to mention purveyors of nighttime subliminal-message CDs that purport to make you quit smoking or love yourself) - but experts acknowledge that more work needs to be done. "I would consider this a very, very small effect," says Paller, so don't expect to be able to boost your SAT score while sleeping just yet.

For nearly two centuries, researchers have suspected that sleep plays an important role in learning and memory. But it's only in the last decade that neuroscientists have discovered the most convincing evidence that memory is indeed dependent on sleep. The prevailing theory is that during deep sleep, the brain replays certain experiences from the day, which, in turn, strengthens the memory of what happened. It is thought that when it comes to factual memories, like names, faces, numbers or locations, memory consolidation happens only during deep sleep - a phase of non–rapid eye movement sleep. (The other broad type of sleep, called rapid eye movement or REM sleep, which is when dreaming occurs, is believed to play a role in consolidating memories involving emotions and motor skills, such as dancing or playing an instrument.)

A minority of neuroscientists disagree that sleep actively aids memory, suggesting instead that consolidation of memories is merely a side effect of snoozing. They argue that the true purpose of sleep is to "cool down" the brain by resting the neurons that have been firing all day long. Paller's study lends support for the majority view: when sounds were played to the sleeping brain, the EEG patterns indicated activity - signaling that perhaps certain memories were being revisited - and this processing appeared to strengthen memories. "The meow somehow stimulated the association of the cat with a certain position on the screen," suggests Jan Born, a memory and sleep researcher at the University of LÜbeck in Germany, who was not involved in the new study.

Born and his team have also been able to influence memory recall during sleep - not with sounds, but with odors. In that study, published in March 2007 in Science, researchers asked people to play a memory card game while the smell of roses wafted through a special face mask. Later that night, when the participants were fast asleep, the same odor was delivered to some of them. The following morning, each person played the same game, and the results were clear: the players who got the nighttime rose odor were significantly better at remembering the card pairs than the group who smelled nothing.

Commenting on the new paper, Born suggests that using sounds is more effective than smells because it lets you choose the memories you want to promote. "Auditory stimuli have the advantage that they can be very specifically linked to visual stimuli," says Born. "With odors, this kind of thing is not possible."

Beyond sensory stimulation during sleep, the timing of sleep may also be important to memory. Recent research suggests that deep sleep can strengthen factual memories, but only if the person naps within 12 hours of learning. In other words, if you have to memorize an SAT word list, you might be better off doing it at night rather than in the morning.

Although researchers are still a long way from understanding exactly how sleep affects memory, they are certain that getting too little sleep is a detriment. A 2007 paper in Nature Neuroscience reported that in addition to consolidating recently learned memories, "sleep before learning is equally important in preparing the brain for next-day memory formation." The study found that people who had skipped a night's sleep fared worse at making new memories the next day, compared with those who had gotten a good night's sleep. Turns out, Mom's advice may have been right all along.

Read "Can a Sleep Disorder Predict Parkinson's?"

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View this article on Time.com

Altruismo

El comportamiento social aprendido y las creencias son elementos mucho más convincentes que la genética para explicar el comportamiento altruista de las personas que hacen favores a desconocidos sin esperar nada a cambio o que arriesgan su vida para salvar las de otros. Ésta es la conclusión a la que han llegado en un estudio Adrian V. Bell y sus colegas de la Universidad de California en Davis. Foto: Zina Deretsky, National Science Foundation El altruismo ha sido desde mucho tiempo atrás un tema de interés para los científicos que estudian la evolución social. El altruismo presenta una paradoja difícil de explicar: Ayudar a personas sin lazos de sangre con el sujeto que ejerce la acción altruista tiene casi siempre un coste o un riesgo para éste, y debido a ello cabría esperar que la conducta altruista, por la amenaza que supone para los descendientes genéticos del individuo altruista, no fuese favorecida por la evolución, al menos atendiendo a los argumentos comunes de ésta. En otras palabras, alguien que arriesga su vida para salvar a desconocidos tiene más probabilidades de morir sin dejar descendientes que alguien que ante todo protege su propia vida. Por eso, el egoísmo debiera ser un rasgo de personalidad heredado de padres a hijos con mucha más frecuencia que el altruismo, hasta acabar desplazando a éste.  Los investigadores utilizaron una ecuación matemática que describe las condiciones necesarias para la evolución del altruismo. Esta ecuación llevó a los autores del estudio a comparar las diferencias genéticas y culturales entre grupos sociales vecinos.  Haciendo uso de los valores previamente calculados sobre las diferencias genéticas, emplearon los datos recopilados en una encuesta mundial sobre valores éticos, los cuales es previsible que estén fuertemente influidos por la cultura en un gran número de países, como una fuente de información para calcular las diferencias culturales entre los mismos grupos vecinos. Al hacer las comparaciones, encontraron que el papel de la cultura tiene un alcance mucho mayor para explicar nuestro comportamiento prosocial que la genética. Scitech News