ScienceDaily (Apr. 19, 2012) — Thinking about death can actually be a good thing. An awareness of mortality can improve physical health and help us re-prioritize our goals and values, according to a new analysis of recent scientific studies. Even non-conscious thinking about death -- say walking by a cemetery -- could prompt positive changes and promote helping others.
Monday, April 23, 2012
Changes in Brain’s Blood Flow Could Cause ‘Brain Freeze’
Findings may eventually lead to new treatments for other types of headache"Findings showed that one particular artery, called the anterior cerebral artery, dilated rapidly and flooded the brain with blood in conjunction to when the volunteers felt pain. Soon after this dilation occurred, the same vessel constricted as the volunteers’ pain receded."
SAN DIEGO— ‘Brain freeze’ is a nearly universal experience—almost everyone has felt the near-instantaneous headache brought on by a bite of ice cream or slurp of ice-cold soda on the upper palate. However, scientists are still at a loss to explain this phenomenon. Since migraine sufferers are more likely to experience brain freeze than people who don’t have this often-debilitating condition, brain freeze may share a common mechanism with other types of headaches, including those brought on by the trauma of blast-related combat injuries in soldiers. One possible link between brain freeze and other headache types is local changes in brain blood flow.
In a new study, Melissa Mary Blatt, Michael Falvo, and Jessica Jasien of the Department of Veterans Affairs New Jersey Health Care System, Brian Deegan and Gearold O Laighin of the National University of Ireland Galway, and Jorge Serrador of Harvard Medical School and the War Related Illness and Injury Study Center of the Veterans Affairs New Jersey Health Care System use brain freeze as a proxy for other types of headaches. By bringing on brain freeze in the lab in volunteers and studying blood flow in their brains, the researchers show that the sudden headache seems to be triggered by an abrupt increase in blood flow in the anterior cerebral artery and disappears when this artery constricts. The findings could eventually lead to new treatments for a variety of different headache types.
An abstract of their study entitled, “Cerebral Vascular Blood Flow Changes During ‘Brain Freeze,’” will be discussed at the meeting Experimental Biology 2012 being held April 21-25 at the San Diego Convention Center. The abstract is sponsored by the American Physiological Society (APS), one of six scientific societies sponsoring the conference, which last year attracted some 14,000 attendees.
Bringing on Brain Freeze
According to study leader Serrador, previous studies meant to assess what physiological changes might prompt headaches have mainly relied on various drugs, or brought in patients already in the throes of a migraine to the lab. However, both methods have their limitations. Pharmacological agents can induce other effects that can make research results misleading, he says, and since researchers can’t wait for migraine sufferers to experience a migraine in the lab, those studies miss the crucial period of headache formation that occurs sometimes hours before scientists were able to study these patients.
To induce headache inside the lab and study it from start to finish, Serrador explains, brain freeze is a perfect fit. It’s easy to bring on and resolves quickly without expensive or complicated equipment or drugs.
In this study, Serrador and his colleague recruited 13 healthy adults. The researchers monitored the volunteers’ blood flow in several brain arteries using transcranial Doppler while they first sipped ice water with the straw pressed against their upper palate—ideal conditions for bringing on brain freeze—and then while sipping the same amount of water at room temperature. The volunteers raised their hand once they felt the pain of a brain freeze, then raised it again once the pain dissipated. Findings showed that one particular artery, called the anterior cerebral artery, dilated rapidly and flooded the brain with blood in conjunction to when the volunteers felt pain. Soon after this dilation occurred, the same vessel constricted as the volunteers’ pain receded.
Changing the Course of Headaches
Serrador and his colleagues speculate that the dilation, then quick constriction, may be a type of self-defense for the brain. “The brain is one of the relatively important organs in the body, and it needs to be working all the time,” he explains. “It’s fairly sensitive to temperature, so vasodilation might be moving warm blood inside tissue to make sure the brain stays warm.” But because the skull is a closed structure, Serrador adds, the sudden influx of blood could raise pressure and induce pain. The following vasoconstriction may be a way to bring pressure down in the brain before it reaches dangerous levels.
He notes that similar alterations in blood flow could be at work in migraines, posttraumatic headaches, and other headache types. If further research confirms these suspicions, then finding ways to control blood flow could offer new treatments for these conditions. Drugs that block sudden vasodilation or target channels involved specifically in the vasodilation of headaches could be one way of changing headaches’ course.
Saturday, April 21, 2012
How Thinking About Death Can Lead to a Good Life
"This tendency for TMT research to primarily deal with negative attitudes and harmful behaviors has become so deeply entrenched in our field that some have recently suggested that death awareness is simply a bleak force of social destruction," says Kenneth Vail of the University of Missouri, lead author of the new study in the online edition ofPersonality and Social Psychology Review this month. "There has been very little integrative understanding of how subtle, day-to-day, death awareness might be capable of motivating attitudes and behaviors that can minimize harm to oneself and others, and can promote well-being."
Past research suggests that thinking about death is destructive and dangerous, fueling everything from prejudice and greed to violence. Such studies related to terror management theory (TMT), which posits that we uphold certain cultural beliefs to manage our feelings of mortality, have rarely explored the potential benefits of death awareness.
In constructing a new model for how we think about our own mortality, Vail and colleagues performed an extensive review of recent studies on the topic. They found numerous examples of experiments both in the lab and field that suggest a positive side to natural reminders about mortality.
For example, Vail points to a study by Matthew Gailliot and colleagues in Personality and Social Psychology Bulletin in 2008 that tested how just being physically near a cemetery affects how willing people are to help a stranger. "Researchers hypothesized that if the cultural value of helping was made important to people, then the heightened awareness of death would motivate an increase in helping behaviors," Vail says.
The researchers observed people who were either passing through a cemetery or were one block away, out of sight of the cemetery. Actors at each location talked near the participants about either the value of helping others or a control topic, and then some moments later, another actor dropped her notebook. The researchers then tested in each condition how many people helped the stranger.
"When the value of helping was made salient, the number of participants who helped the second confederate with her notebook was 40% greater at the cemetery than a block away from the cemetery," Vail says. "Other field experiments and tightly controlled laboratory experiments have replicated these and similar findings, showing that the awareness of death can motivate increased expressions of tolerance, egalitarianism, compassion, empathy, and pacifism."
For example, a 2010 study by Immo Fritsche of the University of Leipzig and co-authors revealed how increased death awareness can motivate sustainable behaviors when pro-environmental norms are made salient. And a study by Zachary Rothschild of the University of Kansas and co-workers in 2009 showed how an increased awareness of death can motivate American and Iranian religious fundamentalists to display peaceful compassion toward members of other groups when religious texts make such values more important.
Thinking about death can also promote better health. Recent studies have shown that when reminded of death people may opt for better health choices, such as using more sunscreen, smoking less, or increasing levels of exercise. A 2011 study by D.P. Cooper and co-authors found that death reminders increased intentions to perform breast self-exams when women were exposed to information that linked the behavior to self-empowerment.
One major implication of this body of work, Vail says, is that we should "turn attention and research efforts toward better understanding of how the motivations triggered by death awareness can actually improve people's lives, rather than how it can cause malady and social strife." Write the authors: "The dance with death can be a delicate but potentially elegant stride toward living the good life."
Your Left Side Is Your Best Side: Our Left Cheek Shows More Emotion, Which Observers Find More Aesthetically Pleasing
ScienceDaily (Apr. 20, 2012) — Your best side may be your left cheek, according to a new study by Kelsey Blackburn and James Schirillo from Wake Forest University in the US. Their work shows that images of the left side of the face are perceived and rated as more pleasant than pictures of the right side of the face, possibly due to the fact that we present a greater intensity of emotion on the left side of our face.
Their work is published online in Springer's journal Experimental Brain Research.
Others can judge human emotions in large part from facial expressions. Our highly specialized facial muscles are capable of expressing many unique emotions. Research suggests that the left side of the face is more intense and active during emotional expression. It is also noteworthy that Western artists' portraits predominantly present subjects' left profile.
Blackburn and Schirillo investigated whether there are differences in the perception of the left and right sides of the face in real-life photographs of individuals.
The authors explain: "Our results suggest that posers' left cheeks tend to exhibit a greater intensity of emotion, which observers find more aesthetically pleasing. Our findings provide support for a number of concepts -- the notions of lateralized emotion and right hemispheric dominance with the right side of the brain controlling the left side of the face during emotional expression.
"Participants were asked to rate the pleasantness of both sides of male and female faces on gray-scale photographs. The researchers presented both original photographs and mirror-reversed images, so that an original right-cheek image appeared to be a left-cheek image and vice versa.They found a strong preference for left-sided portraits, regardless of whether the pictures were originally taken of the left side, or mirror-reversed. The left side of the face was rated as more aesthetically pleasing for both male and female posers.
These aesthetic preferences were also confirmed by measurements of pupil size, a reliable unconscious measurement of interest. Indeed, pupils dilate in response to more interesting stimuli -- here more pleasant-looking faces, and constrict when looking at unpleasant images. In the experiment, pupil size increased with pleasantness ratings