Psych Central News

Detecting Online Liars

2012-02-14T11:54:05Z

People who lie on online dating sites have a huge advantage: Most people can’t identify a liar. But researchers have discovered ways to figure out just who is lying in their profile.

Using personal descriptions written for Internet dating profiles, Catalina Toma, Ph.D., a communication science professor at the University of Wisconsin-Madison, and Jeffrey Hancock, Ph.D., a communication professor at Cornell University, have identified clues as to whether a person is being deceptive.

The researchers compared the actual height, weight, and age of 78 online daters to their profile information and photos on four matchmaking websites. A linguistic analysis then revealed patterns in the liars’ writing.

For example, the more deceptive a dater’s profile, the less likely they were to use the first-person pronoun “I.”

“Liars do this because they want to distance themselves from their deceptive statements,” Toma said. Liars employed negation, a flip of language that restates “happy” as “not sad” or “exciting” as “not boring.” They also tended to write shorter self-descriptions in their profiles — a hedge, Toma said, against weaving a more tangled web of deception.

“They don’t want to say too much,” Toma said. “Liars experience a lot of cognitive load. They have a lot to think about. The less they write, the fewer untrue things they may have to remember and support later.”

Those who lied about their age, height or weight also were more likely to talk about work or life achievements, rather than appearance, the researcher noted.

Once the researchers had these tools, they were able to identify the liars about 65 percent of the time, Toma said.

In a second phase of the study, Toma and Hancock asked volunteers to judge the person’s trustworthiness based solely on the written self-descriptions posted on their online profiles.

“As we expected, people are just bad at this,” Toma said. “They might as well have flipped a coin. They’re looking at the wrong things.”

About 80 percent of the 78 profiles in the study, which was supported by the National Science Foundation, strayed from the truth on some level, she adds. “Almost everybody lied about something, but the magnitude was often small,” Toma said.

Weight was the most frequent transgression, with women off by an average of 8.5 pounds and men by 1.5 pounds on average. Half lied about their height, and nearly 20 percent changed their age.

Toma says the findings are not out of line with what we know about liars in face-to-face situations.

“Online daters’ motivations to lie are pretty much the same as traditional daters’,” she said. “It’s not like a deceptive online profile is a new beast, and that helps us apply what we can learn to all manners of communication.”

Don’t go looking for a dating site that employs Toma’s linguistic analysis as a built-in lie detector.

“Someday there may be software to tell you how likely it is that the cute person whose profile you’re looking at is lying to you, or even that someone is being deceptive in an email,” Toma said. “But that may take a while.”

The study was published in the February issue of the Journal of Communication.

Source: University of Wisconsin-Madison

Weight and Body Image Program Helps Teen Girls

2012-02-14T12:41:18Z

Researchers report success in a primary care-directed weight management program designed specifically for teenage girls.

Results from the six-month program included less weight gain, improved body image, less consumption of fast food and more participation in family meals. The program included weekly peer meetings, consultations with primary care providers and separate meetings for parents.

Kaiser Permanente researchers have published their results online in the journal Pediatrics.

Experts say the study is the first to report long-term results from a weight management program designed specifically for teenage girls.

Most other programs have included younger children and interventions focused on the entire family. This program included separate meetings for parents with the rationale that teens are motivated more by peer acceptance than parental influence.

The study is also unique in that it was conducted in a primary-care setting, rather than an academic or specialty-care environment.

“Nearly one-third of teenage girls are overweight or obese, and many of them are likely to become obese adults,” said Lynn DeBar, Ph.D., M.P.H., lead author and senior investigator with the Kaiser Permanente Center for Health Research.

“Our study shows that intervention programs can help these girls achieve long-term success managing their weight and also learning new habits that will hopefully carry over into their adult life.”

“Many teenage girls are still growing taller, so for them, maintaining weight or slowing weight gain is an acceptable goal,” said Phil Wu, M.D., a pediatrician who leads Kaiser Permanente’s effort to prevent and treat childhood obesity and is also a co-author of the study.

“Girls in the program gained less weight than those who weren’t in the program, and they reduced their overall body mass index, improved their self-image and developed healthy lifestyle habits, so all of these are successes.”

Researchers followed 208 girls, ages 12-17. All of the girls were classified as overweight or obese, according to standards set by the Centers for Disease Control and Prevention standards.

Half of the girls were assigned to the intervention group and half to usual care.

Girls in the intervention group met weekly with their peers and a behavioral counselor during the first three months, and then every other week during months four and six.

The girls were weighed and asked to keep a food and activity diary, which they discussed during each meeting. The program focused on decreasing portion size, limiting consumption of energy-rich foods, establishing regular meal patterns, substituting water for sugar-sweetened beverages, reducing fast food, increasing fruit and vegetable consumption, and having more family meals.

A significant exercise prescription was delivered with girls encouraged to exercise at least five days a week for 30-60 minutes. Moreover, screen time was to be limited to two hours a day.

Participants also received yoga instruction, and a physical-activity video game to use at home. Discussion topics included ways to avoid disordered eating, coping with family and peer teasing and developing strategies to combat negative self-talk.

An important part of the problem included parental education on support for their daughters. This weekly meeting was not held in the presence of the daughters.

Health care providers received summaries of the girls’ current health habits, including meal and physical activity patterns. After receiving training in motivational techniques, the providers met with the girls at the beginning of the study to help them choose one or two behaviors to work on.

The providers had a second visit with the girls at the end of the six-month intervention to check their progress.

Girls assigned to the usual-care group received a packet of materials that included a list of online reading about lifestyle changes. They also met with their primary care provider at the beginning of the study, but the providers were not given health habit summaries for these girls.

Both groups had health assessments and lab tests at the beginning of the study, at six months, and then again at 12 months. The girls started out with an average weight in the 190 lb. range, and an average body mass index in the 97th percentile, which by CDC standards is considered to be obese.

At the end of the study, girls who participated in the program were in the 95th percentile, while girls in the usual-care group were in the 96th percentile.

Researchers say the weight changes were statistically significant but modest compared to some other weight loss interventions.

They point out that the girls were severely obese to begin with and possibly treatment-resistant due to previous involvement in other weight loss programs.

A salient feature of the program was a de-emphasis on calorie counting, focusing instead on lifestyle changes. However, researchers acknowledge that this approach may have produced more modest weight changes than they had expected.

This study is part of ongoing Kaiser Permanente research into weight loss. Previous studies include:

A Kaiser Permanente Center for Health Research study published in the International Journal of Obesity in 2011 found that people trying to lose at least 10 pounds were more likely to reach that goal if they had lower stress levels and slept more than six hours, but not more than eight hours, a night.
Another Kaiser Permanente Center for Health Research study published in 2010 found that the more people logged on to an interactive weight management website, the more weight they kept off.
Researchers at the Kaiser Permanente Center for Health Research also reported in a 2008 study that keeping a food diary can double a person’s weight loss and that both personal contact and Web-based support can help with long-term weight management.

Source: Kaiser Permanente

Overweight teenager photo by shutterstock.

Exercise Commitment Wavers with Motivation

2012-02-14T11:49:39Z

A new study by Penn State researchers finds that motivation to exercise fluctuates from week to week. And, not surprisingly, the motivational fluctuations predict whether we will be physically active.

In an effort to understand how the motivation to exercise is linked to behavior, researchers examined college students’ intentions to be physically active as well as their actual activity levels.

“Many of us set New Year’s resolutions to be more physically active, and we expect these resolutions to be stable throughout the year,” said David Conroy, Ph.D., professor of kinesiology.

“One of the things we see in this study is that from week to week our motivation can change a lot, and these weekly changes in motivation can be destructive to our resolutions.”

Investigators recruited 33 college students and assessed over a 10-week period both the students’ weekly intentions to be physically active and their activity levels.

Participants were instructed to log on to a website and to rate their intentions to perform physical activity for the week ahead. To assess physical activity, participants were instructed to wear pedometers each day for the first four weeks.

Researchers discovered that for many of the participants, the motivation to exercise fluctuated on a weekly basis, and these fluctuations were linked to their behavior.

The findings from the study appear in the current issue of the Journal of Sport & Exercise Psychology.

“Our motivation to be physically active changes on a weekly basis because we have so many demands on our time,” said Conroy.

For most of us, the challenge to remain motivated to exercise in the weeks when we are maxed-out is problematic. “Maybe one week we’re sick or we have a work deadline — or, in the case of students, an upcoming exam.”

According to Conroy, the lapses in motivation really seem to be destructive.

“Our results suggest that people with consistently strong intentions to exercise have the best chance of actually following through on their intentions, while people with the greatest fluctuations in their motivation have the hardest time using that motivation to regulate their behavior.”

A solution for individuals with wavering motivation includes incorporating physical activity into their daily lives, said research assistant Amanda Hyde.

“Maybe the way to get these people to be more physical active isn’t necessarily by increasing their motivation,” she said, ” but rather by changing the way they do things in their lives so exercise automatically fits within their schedule, like walking to work rather than driving or taking the stairs rather than the elevator.”

Conroy added that consistency of intentions is not the only thing that matters in predicting whether or not a person will be active. It also matters if it is a weekday or the weekend.

“We saw that people who consistently reported stronger intentions to be active were more active during the week, but then on weekends the pattern flipped for them,” said Conroy. “If a person was really motivated during the week, then he or she crashed on the weekend.”

This finding may be unique to the student population as an opposite behavior – that of limited exercise during the week, then over-exercising on the weekend – is often displayed by the working professional a/k/a “weekend warrior.”

Conroy noted that people seem to have different systems that motivate their behavior during the week and on the weekend.

In the case of college students, “individuals may be exhausted from having regulated their behavior and managed their time so carefully during the week that on the weekends they need to recharge their batteries and throw their time management out of the window.”

Regarding New Year’s resolutions, Conroy advised that people should focus less on making broad commitments to becoming more active and instead come up with a plan for how they’re going to sustain their motivation from one week to the next.

“It is important to pay attention to how we can sustain a high level of motivation and not just let that motivation degrade in response to all the external demands we face,” said Conroy.

Source: Penn State

Dietary Intake Linked to Memory Loss in Seniors

2012-02-14T11:48:51Z

We all recognize that overeating can cause weight gain, but now new research suggests excessive calorie consumption can double the risk of memory loss in older adults.

In a paper presented during the American Academy of Neurology’s Annual meeting, researchers report that consumption of between 2,100 and 6,000 calories per day may double the risk of mild cognitive impairment (MCI), among people age 70 and older.

The finding is significant as MCI is the stage between normal memory loss that comes with aging and early Alzheimer’s disease.

Mayo Clinic investigators discovered the more calories consumed each day, the higher the risk of MCI.

“We observed a dose-response pattern,” said study author Yonas E. Geda, M.D., M.Sc., with the Mayo Clinic in Scottsdale, Arizona.

Researchers followed 1,233 people between the ages of 70 and 89 and free of dementia residing in Olmsted County, Minn. Of those, 163 had MCI. Participants reported the amount of calories they ate or drank in a food questionnaire and were divided into three equal groups based on their daily caloric consumption.

The natural experiment resulted in a group that consumed between 600 and 1,526 calories per day; another group with caloric intake between 1,526 and 2,143 per day; and a third group that devoured between 2,143 and 6,000 calories per day.

Investigators discovered the odds of having MCI more than doubled for those in the highest calorie-consuming group compared to those in the lowest calorie-consuming group.

Researchers found the risk remained after adjusting for history of stroke, diabetes, amount of education, and other factors that can affect risk of memory loss.

There was no significant difference in risk for the middle group.

“Cutting calories and eating foods that make up a healthy diet may be a simpler way to prevent memory loss as we age,” said Geda.

Source: American Academy of Neurology

Experience Fails to Improve Rational Decision-Making

2012-02-14T13:13:23Z

A sobering new study finds that many people have difficulty making informed decisions over situations that involve risk. And even when the probability of outcomes is known, we continue to make decisions at odds with probability.

Researchers from New York University and Université Paris Descartes, have published their findings in the journal Psychological Science.

In the study, researchers used questions about gambling, where information about probabilities is given explicitly in numerical form. For instance, in experiments, participants may be asked, “Would you rather have a 50:50 chance of winning $100 or otherwise $0, or would you rather just take $40?”

The consensus in the field is that decision makers, confronted with such possibilities, make poor decisions. They do not maximize their possible winnings, and sometimes their choices are logically inconsistent with one another.

However, investigators realized that in our everyday life we are rarely given explicit estimates of probability. Therefore, what probability information people have is based primarily on their own past experience.

In fact, researchers in several laboratories have conjectured that, when information about probability is learned through experience, people make better decisions.

The researchers at NYU and Université Paris Descartes wanted to test this claim. In the Psychological Science study, participants first played a video game that included firing computerized bullets at different-sized rectangles on the screen. The game was set up so the bullets took a zig-zagging trajectory and, as a result, often missed their target.

This meant the chances of hitting a rectangle increased with its size—it was simply easier to strike a bigger target, and participants gradually learned the link between rectangle size and probability.

Following training, the researchers compared performance in two different decision tasks.

The first was a “classical” decision task where participants chose between alternatives with the probabilities of different outcomes clearly presented. The participant always chose between a larger probability of getting $1 and a smaller probability of getting $2.

In the second (decision from experience), though, they saw two rectangle targets differing in size. They were told that the larger target was worth $1 if they hit it while the smaller—and harder to hit—target was worth $2.

The experimenters adjusted the size of the larger rectangle so that the participant’s probability of hitting it was matched to the larger probability in the “classical” task.

They adjusted the size of the smaller rectangle so that the participant’s probability of hitting it was identical to the smaller probability in the “classical” task. As a result, the motor and classical decision tasks were mathematically identical.

Despite hundreds of trials of training, participants were still markedly sub-optimal in the decision-from-experience task. They showed the same kind of misuse of probability as found in typical decision tasks with probabilities explicitly presented in numerical form.

In summary, practice alone isn’t enough to get people to make good decisions based on risk, said Dr. Laurence Maloney, a professor in NYU’s Center for Neural Science and Department of Psychology, one of the study’s co-authors.

“You could imagine taking someone and saying, well, let’s practice them over and over and over again until they’re experts and maybe their decision-making will be perfect,” he said, adding that’s not what happened in his experiment.

“Basically, the key idea is that people have a distorted appreciation of probability, and it doesn’t go away even when you become one of the world’s experts at shooting rectangles.”

Source: New York University

Numerical Literacy May Aid Decision-Making

2012-02-13T11:44:41Z

Do remember your high school math teacher? Or, perhaps an elementary school teacher who drilled you on the multiplication tables?

If you have a positive memory of the schooling, and feel reasonably comfortable with numbers, you are probably better at making informed decisions on a plethora of numerological topics including health risks, investment alternatives, calories, etc.

A new study reviews how people with strong numerical literacy — that is, individual who understand numbers better and process information differently — ultimately make more informed decisions.

The article, published in Current Directions in Psychological Science, explores how people who are numerate feel comfortable thinking about numbers and are less influenced by other information, said Ellen Peters, Ph.D., of Ohio State University, the author of the new paper.

For example, in one of Peters’s studies, students were asked to rate undergraduates who received what looked like different test scores.

Numerate people were more likely to see a person who got 74 percent correct and a person who got 26 percent incorrect as equivalent, while people who were less numerate thought people were doing better if their score was given in terms of a percent correct.

Investigators say this type of analysis is necessary for many forms of decision-making.

For example, “A lot of people take medications,” Peters says. Every drug has benefits and potential risks, and those can be presented in different ways. “You can talk about the 10 percent of the population that gets the side effect or the 90 percent that does not.”

For individuals who are less numerate, the method by which the information is presented is critical.

Other research has shown that only less numerate people respond differently to something that has a 1 in 100 chance of happening than something that has a 1 percent chance of happening. The less numerate see more risk in the 1 in 100 chance — even though these numbers are exactly the same.

Researchers believe the findings have implications for how policy makers and others should communicate about the risks of medicines, earthquakes, climate change, and the stock market.

“Numbers are really just abstract symbols, and we have to bring meaning to them somehow,” Peters said. “In general, people who are numerate are better able to bring consistent meaning to numbers and to make better decisions.

“It suggests that courses in math and statistics may be the educational gift that keeps on giving.”

Source: Association for Psychological Science

Boy with numbers photo by shutterstock.

Is 9 Hours of Sleep Too Much for Teens?

2012-02-13T11:43:51Z

New research challenges federal guidelines that encourage high school students to receive nine hours of sleep a night.

The Brigham Young University study found that 16- to 18-year-olds perform better academically when they sleep for 7 hours.

“We’re not talking about sleep deprivation,” said study author Eric Eide. “The data simply says that seven hours is optimal at that age.”

The new study by Eide and fellow BYU economics professor Mark Showalter is the first in a series of studies where they examine sleep and its impact on health and education.

Current federal guidelines are based on studies where teens were simply told to keep sleeping until they felt satisfied.

“If you used that same approach for a guideline on how much people should eat, you would put them in a well-stocked pantry and just watch how much they ate until they felt satisfied,” Showalter said.

“Somehow that doesn’t seem right.”

BYU investigators attempted to devise a scientific study that matched the amount of sleep to academic performance or productivity.

Analyzing data from a representative sample of 1,724 primary and secondary school students across the country, they found a strong relationship between the amount of sleep youths got and how they fared on standardized tests.

But more sleep isn’t always better. As they report in the Eastern Economics Journal, the right amount of sleep decreases with age:

The optimal for 10-year-olds is 9 – 9.5 hours;
The optimal for 12-year-olds is 8 – 8.5 hours;
The optimal for 16-year-olds is 7 hours.

“We don’t look at it just from a ‘your kid might be sleeping too much’ perspective,” Eide said.

“From the other end, if a kid is only getting 5.5 hours of sleep a night because he’s overscheduled, he would perform better if he got 90 minutes more each night.”

The size of the effect on test scores depends on a number of factors, but an 80-minute shift toward the optimum is comparable to the child’s parents completing about one more year of schooling.

“Most of our students at BYU, especially those that took early-morning seminary classes in high school, are going to realize that 9 hours of sleep isn’t what the top students do,” Showalter said.

Source: Brigham Young University

Sleeping teenager photo by shutterstock.

Natural Disasters Influence Mental Mistakes

2012-02-13T11:45:28Z

A new study finds that survivors of natural disasters may experience intellectual challenges in addition to stress and anxiety. This mental decline may cause survivors to make serious errors in their daily lives.

Experts say attention to these phenomena is important given the prevalence of hurricanes, tornados and earthquakes.

The study on how cognitive performance can decline after earthquakes is published by New Zealand researchers in the journal Human Factors.

In the report, University of Canterbury’s William S. Helton and James Head discuss how prior studies have found that more traffic accidents and accident-related fatalities occur following human-made disasters such as the September 11, 2001, terrorist attacks.

Experts believe the mishaps are due to increased cognitive impairment that can lead to higher stress levels and an increase in intrusive thoughts. However, until this time, no research has been conducted on the effects of natural disasters on cognitive performance.

The authors were unexpectedly presented with a unique opportunity to investigate the impact of the devastating 2010 earthquake in Christchurch, New Zealand, as they were performing a human performance study with community members at the time of the quake.

“We were conducting a [different] study on human performance requiring two sessions,” said Helton.

“In the midst of the study, between the two sessions, we had a substantial local earthquake, which resulted in the rare opportunity to do a before/after study. We were quick to seize the opportunity.”

Investigators measured participants’ cognitive control by asking them to either press a button corresponding to numbers presented on a video screen or to withhold a response to a preselected number presented on the same screen.

Normally, participant performance would improve during the second session, but the authors found an increase in errors of omission following the earthquake.

Helton and Head also noted distinct differences in pre- and post-earthquake findings depending on self-reported responses to the disaster: If the participants reported being anxious following the quake, their response times sped up and they made more errors of commission, whereas those who reported depression logged slower response times.

Researchers believe the study substantiates the phenomenon many people report experiencing after a major event like an earthquake.
“People would find themselves zoning out and making more errors than usual after the quake.”

Investigators believe future research is needed to explore this phenomenon further, but the scientists’’ findings may point to potentially serious complications arising from post-disaster performance in daily life and work tasks.

These findings also suggest that police, emergency responders, and others working in the aftermath of the disaster may also experience cognitive disruption, which can interfere with their ability to perform rescue-related tasks.

“Presumably people are under increased cognitive load after a major disaster,” Helton continued.

“Processing a disaster during tasks is perhaps similar to dual-tasking, like driving and having a cell phone conversation at the same time, and this can have consequences.”

Source: Human Factors and Ergonomics Society

Natural disasters photo by shutterstock.

No Age Limit for Online Dating, But Different Values

2012-02-13T11:45:04Z

Online dating is not limited to the young; in fact, individuals over the age of 60 are its fastest growing age group. But new research suggests what they value is light-years away from hot looks and tony clubs.

A dearth of data about online dating in later life prompted two Bowling Green State University gerontologists to look into the phenomenon.

In their research, Drs. Wendy K. Watson and Charlie Stelle aim to increase the quantity and improve the quality of information available about dating in later life, and in this case, online dating.

Although the research is in the early stage, Watson and Stelle are finding that older adults appear to market themselves differently on online dating sites than younger adults.

Most notable is the absence of physical appearance (looks) and status. Evidence suggests the senior population appears to be more interested in honest self-representation, compatibility and companionship rather than discussing areas such as sexual prowess and nightlife.

The researchers found traditional online coding terms used to describe younger generations seem to “miss some key elements relevant for ads placed by older adults.”

Watson and Stelle suggest online sites geared at those over 60 might want to consider adding personal characteristics such as affection, intelligence, independence, purpose and goals, religion and spirituality, political beliefs, health and status.

Interestingly, the language of seniors’ online ads was different when describing themselves and what they were looking for in a relationship. Terms such as “young at heart” and “active” were used to show physical fitness and good health.

In previous research on dating in later life, Watson and Stelle found that older women had specific expectations regarding dating.

Watson said women don’t have a need that has to be filled. “Instead their philosophy is: ‘Please don’t waste my time,’” she said.

“They are less likely to play games,” Stelle said. “They want to make a decision quickly and cut their losses, because they have learned life is too short for dating games.”

In the future, Watson and Stelle will continue their research and expand the analysis within the match.com and ourtime.com dating sites.

The experts say their findings show that the desire to find love and a companion to share life with has no expiration date.

Source: Bowling Green State University

Eledrly lady on a computer photo by shutterstock.

New Treatment Target for Alzheimer’s

2012-02-12T21:45:21Z

A new link has been identified between short-term memory and a protein called beta-arrestin that could blaze a new path toward the therapeutic treatment of neurological disorders, especially Alzheimer’s disease. The discovery was made by biomedical scientists at the University of California, Riverside.

This is the first study that has linked beta-arrestin to Alzheimer’s and learning and memory.

Beta-arrestin is expressed in various cells of the body, including the hippocampus, an area of the brain connected to learning and the formation of short-term memories. Beta-arrestin is one of many “scaffolding proteins”—proteins that support neuron connections. The absence of beta-arrestin has been shown to impair normal learning in mice.

In the hippocampus, new connections called synapses continue to form between neurons. When the brain learns something new, connections are formed and some old ones are strengthened through a process known as long-term potentiation (LTP).

However, since brains have only a limited capacity, other old connections must disassemble through a process called long-term depression (LTD) in order for new synapses to form.

Beta-arrestin ensures the plasticity of synaptic connections and LTD by regulating the “actin cytoskeleton,” a network of proteins that shapes the “backbone” of neurons and helps form new synaptic connections and disassembles old ones.

“In some pathological conditions such as Alzheimer’s disease, loss of the old synaptic connections far exceeds the formation of new ones, resulting in overall loss of synapses and short-term memory loss,” said Iryna M. Ethell, an associate professor of biomedical sciences and the lead author of the research paper.

“Our work, done on mice, shows that if beta-arrestin is removed from neurons, this loss of synapses is prevented. But we also know that beta-arrestin is required for normal learning and memory; so a fine balance needs to be established. This balance could be easily achieved by pharmaceutical drugs in the future.”

Beta-arrestin can be visualized as energy given to a puppeteer (actin cytoskeleton) who controls the strings of a puppet (interneuronal connection), explains Ethell. In order for a person to learn something, the puppeteer needs to move the strings in a specific order.

However, in patients with Alzheimer’s, this energy supply overactivates and the strings are pulled in a disorderly fashion that results in the strings being broken (loss of synapses) and the puppets collapsing. Although the removal of beta-arrestin would avoid this collapse, a complete loss of the protein would result in no movement of the puppets at all (no learning in the brain).

“A selective tuning of beta-arrestin activity is therefore necessary to partially reduce synapse disassembly,” said Crystal G. Pontrello, the first author of the research paper and a postdoctoral researcher in Ethell’s lab. “What you want, ideally, is the elimination of only some unused old synaptic connections so that there is room to make new connections.”

The research is published in the Proceedings of the National Academy of Sciences.

Source: University of California-Riverside

Obesity Linked to Altered Functioning of Reward System

2012-02-11T15:38:58Z

In obese vs. thin individuals, brain glucose metabolism appears to be much higher in the brain’s striatal regions — areas associated with reward processing, according to researchers at the University of Turku and Aalto University.

Furthermore, an obese person’s reward system seems to respond more vigorously to food pictures, whereas their responses in the frontal cortical regions involved in cognitive function appear lessened.

Since the central nervous system is highly involved in the processing of hunger signals and food intake control, researchers suggest that the cause of obesity might be rooted in the brain. For the study, researchers used various brain imaging methods to measure the involved brain circuits in morbidly obese individuals as well as in lean controls.

Brain glucose metabolism was measured with positron emission tomography during conditions in which the participant’s body was satiated in terms of insulin signaling. Brain responses to food pictures were observed with functional magnetic resonance imaging.

“The results suggest that obese individuals’ brains might constantly generate signals that promote eating even when the body would not require additional energy uptake,” says adjunct professor Lauri Nummenmaa from the University of Turku.

“The results highlight the role of the brain in obesity and weight gaining. The results have major implications on the current models of obesity, but also on development of pharmacological and psychological treatments of obesity,” Nummenmaa says.

Source: Academy of Finland

Age of Both Parents Linked to Autism

2012-02-11T15:37:33Z

Older mothers and fathers are more likely to have a child with autism, according to a recently published study led by researchers at The University of Texas Health Science Center at Houston (UTHealth).

The researchers compared 68 age- and sex-matched, case-control pairs from their research in Jamaica, where UTHealth has been studying autism in collaboration with The University of the West Indies in Kingston, Jamaica.

“This should put to rest discrepancies in previous studies showing that just maternal age or just paternal age are linked to having a child with autism,” said Mohammad Hossein Rahbar, Ph.D., principal investigator and professor of epidemiology and biostatistics at The University of Texas School of Public Health, part of UTHealth. “Our results revealed that the age of the father and the mother are jointly associated with autism in their children.”

The study found that mothers who had children with autism were on average 6.5 years older than women who did not have a child with autism. The corresponding age difference for fathers was 5.9 years.

Previous studies used statistical models that made it hard to assess both maternal and paternal age as joint risk factors, a problem called multicollinearity, Rahbar said, noting he was able to use more complex statistical models to avoid the problem.

The research was published this month in the Journal of Autism and Developmental Disorders.

Source: The University of Texas Health Science Center at Houston (UTHealth)

Tai Chi May Help Parkinson’s Patients

2012-02-10T11:47:06Z

Tai chi training can help patients with mild to moderate Parkinson’s disease increase stability and avoid falls.

In an exercise study conducted by researchers at the Oregon Research Institute, tai chi training resulted in improved postural stability and walking ability, as well as reduced falls in the participants.

“These results are clinically significant because they suggest that Tai Chi, a low-to-moderate impact exercise, may be used as an add-on to current physical therapies, to address some of the key clinical problems in Parkinson’s disease, such as postural and gait instability,” said Fuzhong Li, Ph.D.

“Since many training features in the program are functionally oriented, the improvements in the balance and gait measures that we demonstrated highlight the potential of tai chi-based movements in rehabilitating patients with these types of problems and, consequently, easing cardinal symptoms of Parkinson’s disease and improving mobility, flexibility, balance, and range of motion.”

In the four-year project funded by the National Institute of Neurological Disorders and Stroke, researchers randomly assigned 195 patients to one of three exercise groups: tai chi, resistance training, or stretching. The patients participated in 60-minute exercise sessions twice a week for 24 weeks.

The results of the study showed that the tai chi group performed consistently better than the stretching group in how far they could lean in any direction without losing balance, as well as demonstrating better levels of directional control of the body and walking ability, such as longer stride length. tai chi participants also outperformed those in the resistance training group on the balance and stride length measures.

Finally, tai chi training was shown to significantly lower the incidence of falls compared to stretching, and was as equally effective as resistance training in reducing falls.

As Parkinson’s disease progresses, patients lose stability and have trouble walking, difficulty managing activities required of daily living, and experience frequent falls. Exercise is an important part of the management of Parkinson’s disease because physical activity has been shown to retard the deterioration of motor function and to prolong functional independence. However, research on alternative forms of exercise, such as tai chi, that could improve balance, gait, and function in patients with Parkinson’s disease is scarce, the researcher notes.

The program developed by Li consisted of six tai chi movements integrated into a routine that focused on weight-shifting, controlled-displacement of the center of gravity over the base of support, ankle sway, and front-to-back and sideways stepping. Natural breathing was integrated into the training routine.

“There are a number of practical advantages to using tai chi to improve motor dysfunction of Parkinson’s disease,” he said. “It is a low-cost activity that does not require equipment, it can be done anywhere, at any time, and the movements can be easily learned. It can also be incorporated into a rehabilitation setting as part of existing treatment. Similarly, because of its simplicity, certain aspects of this tai chi program can also be prescribed to patients as a self-care/home activity.”

Source: Oregon Research Institute

Elderly man performing tai chi photo by shutterstock.

Depressed Adolescents More Likely to be Bullied

2012-02-10T11:46:06Z

Adolescents who suffer from depression are more likely to have problems with peer relationships, including being bullied at school, according to a new study.

And while it is often assumed that being bullied leads to psychological problems, such as depression, the new study does not support that direction of influence, researchers said.

“Often the assumption is that problematic peer relationships drive depression. We found that depression symptoms predicted negative peer relationships,” said Karen Kochel, Ph.D., Arizona State University School of Social and Family Dynamics assistant research professor. “We examined the issue from both directions but found no evidence to suggest that peer relationships forecasted depression among this school-based sample of adolescents.”

The new research, published in the journal Child Development, found that being depressed in fourth grade predicted bullying in fifth grade and difficulty with peer acceptance in sixth grade.

The researchers examined data from 486 children from fourth to sixth grade. Parents, teachers, peers, and students provided information through yearly surveys. Data was collected as part of a large-scale study that began in 1992 and continued for nearly two decades.

Teachers and parents were asked to identify classic signs of depression, such as crying a lot or a lack of energy. They defined peer victimization as bullying that was manifested physically, verbally, or relationally, such as hitting someone, saying mean things, talking behind someone’s back, or picking on someone.

Research shows that having positive peer relationships is crucial for adapting to certain aspects of life, such as scholastic achievement and functioning in a healthy manner psychologically, she added.

“If adolescent depression forecasts peer relationship problems, then recognizing depression is very important at this particular age,” she said. “This is especially true given that social adjustment in adolescence appears to have implications for functioning throughout an individual’s lifetime.”

School may be the best place to address signs of depression since students typically start spending more time with their friends and less with their parents as they become adolescents, according to researchers.

“We studied peer relationships within the school context. Parents tend not to observe these relationships,” Kochel said. “Because depression has the potential to undermine the maturation of key developmental skills, such as establishing healthy peer relationships, it’s important to be aware of the signs and symptoms of adolescent depression.”

The study was funded by the National Institutes of Health.

Source: Arizona State University

Self-Fulfilling Perception of Health

2012-02-10T11:44:02Z

Researchers have learned that the answer an individual gives when asked to rate their health is associated with an individual’s probability of survival or death.

Needless to say, a pessimistic assessment goes hand in hand with an increased risk of illness or death. It can be assumed that on average people who rate their health as poor have an unhealthier lifestyle, are often in a fragile state of health or are already sick.

However, earlier studies that only monitored the participants for a few years after the survey reveal that the correlation persists even if these factors are taken into account.

In the new study by researchers at the University of Zurich, investigators demonstrated that self-rated health is also linked to the probability of survival or death over a long period of more than thirty years.

In the study, which was conducted in Switzerland, men who rated their health as “very poor” were 3.3 times more likely to die than men of the same age who rated their health as “excellent”, and the risk of death was 1.9 times higher in women who rated their health as “very poor” than for those who rated it as “excellent”.

Here, the risk increased steadily from an optimistic to a pessimistic rating: people in “excellent” health had better chances of survival than those in “good” health, the latter better chances than those in a “fair” state of health, and so on.

“The steady increase in risk and the long time of over thirty years between the self-rating and the end of the observation period render it practically impossible for medical history or a dark foreboding to be main causes of the correlation observed,” explains head of the study Matthias Bopp.

When investigators statistically removed confounding variables, such as education levels, marital status, tobacco-related strains, medical history, the use of medication, blood pressure and blood glucose into account, the correlation between self-rated health and mortality only remained strong.

The difference in the risk of death between the best and the worst rating was still 1:2.9 in men and 1:1.5 in women.

“Our results indicate that people who rate their state of health as excellent have attributes that improve and sustain their health,” concludes specialist in preventive medicine David Fäh.

“These might include a positive attitude, an optimistic outlook and a fundamental level of satisfaction with one’s own life.”

The results of the study support the broad concept of health advocated by the World Health Organization not as the absence of disease, but rather as complete physical, mental and social wellbeing.

In the future, investigators hope that an individual’s uncertain view of health will trigger positive holistic strategies to improve an individual’s outlook on life.

“Good doctors should therefore not just look for the presence of risk factors or diseases, but also check which health resources their patients have and boost and consolidate them if need be,” says David Fäh.

Source: University of Zurich

Elwely woman and doctor looking out window photo by shutterstock.