Posts tagged psychology
Articles and news from the latest research reports.
Higher-math skills entwined with lower-order magnitude sense
The ability to learn complex, symbolic math is a uniquely human trait, but it is intricately connected to a primitive sense of magnitude that is shared by many animals, finds a study to be published by the Proceedings of the National Academy of Sciences (PNAS).
"Our results clearly show that uniquely human branches of mathematics interface with an evolutionarily primitive general magnitude system," says lead author Stella Lourenco, a psychologist at Emory University. "We were able to show how variations in both advanced arithmetic and geometry skills specifically correlated with variations in our intuitive sense of magnitude."
Babies as young as six months can roughly distinguish between less and more, whether it’s for a number of objects, the size of objects, or the length of time they see the objects. This intuitive, non-verbal sense of magnitude, which may be innate, has also been demonstrated in non-human animals. When given a choice between a group of five bananas or two bananas, for example, monkeys will tend to take the bigger bunch.
"It’s obviously of adaptive value for all animals to be able to discriminate between less and more," Lourenco says. "The ability is widespread across the animal kingdom – fish, rodents and even insects show sensitivity to magnitude, such as the number of items in a set of objects."
Primates’ brains make visual maps using triangular grids
Primates’ brains see the world through triangular grids, according to a new study published online Sunday in the journal Nature.
Scientists at Yerkes National Primate Research Center, Emory University, have identified grid cells, neurons that fire in repeating triangular patterns as the eyes explore visual scenes, in the brains of rhesus monkeys.
The finding has implications for understanding how humans form and remember mental maps of the world, as well as how neurodegenerative diseases such as Alzheimer’s erode those abilities. This is the first time grid cells have been detected directly in primates. Grid cells were identified in rats in 2005, and their existence in humans has been indirectly inferred through magnetic resonance imaging.
Grid cells’ electrical activities were recorded by introducing electrodes into monkeys’ entorhinal cortex, a region of the brain in the medial temporal lobe. At the same time, the monkeys viewed a variety of images on a computer screen and explored those images with their eyes. Infrared eye-tracking allowed the scientists to follow which part of the image the monkey’s eyes were focusing on. A single grid cell fires when the eyes focus on multiple discrete locations forming a grid pattern.
"The entorhinal cortex is one of the first brain regions to degenerate in Alzheimer’s disease, so our results may help to explain why disorientation is one of the first behavioral signs of Alzheimer’s," says senior author Elizabeth Buffalo, PhD, associate professor of neurology at Emory University School of Medicine and Yerkes National Primate Research Center. "We think these neurons help provide a context or structure for visual experiences to be stored in memory."
"Our discovery of grid cells in primates is a big step toward understanding how our brains form memories of visual information," says first author Nathan Killian, a graduate student in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. "This is an exciting way of thinking about memory that may lead to novel treatments for neurodegenerative diseases."
(Image credit: Mark Snelson)
Yeast model offers clues to possible drug targets for Lou Gehrig’s disease
Amyotrophic lateral sclerosis, also called Lou Gehrig’s disease, is a devastatingly cruel neurodegenerative disorder that robs sufferers of the ability to move, speak and, finally, breathe. Now researchers at the Stanford University School of Medicine and San Francisco’s Gladstone Institutes have used baker’s yeast — a tiny, one-celled organism — to identify a chink in the armor of the currently incurable disease that may eventually lead to new therapies for human patients.
“Even though yeast and humans are separated by a billion years of evolution, we were able to use the power of yeast genetics to identify an unexpected potential drug target for ALS,” said Aaron Gitler, PhD, an associate professor of genetics at Stanford. “Many neurodegenerative disorders such as ALS, Parkinson’s and Alzheimer’s exhibit protein clumping or misfolding within the neurons that is thought to either cause or contribute to the conditions. We are trying to figure out why these proteins aggregate in neurons in the brain and spinal cord, and what happens when they do.”
In 2008, Gitler received a New Innovator award from the National Institutes of Health to use yeast as a model for understanding human neurodegenerative diseases and as a way to identify new targets for drug development.
(Source: med.stanford.edu)
Death: A special report on the inevitable
The only certain thing in life is that it will one day end. That knowledge is perhaps the defining feature of the human condition. And, as far as we know, we alone are capable of contemplating the prospect of our demise. In these articles we explore the implications: the shifting definition of death, how knowing that we will die gave birth to civilisation, the grim reality of decomposition and whether it makes sense to fear death. But first, when did we become aware of our own mortality?
Bird-brains solve problems spontaneously
In certain situations animals can spontaneously solve problems without planning their actions, according to research from The University of Auckland’s School of Psychology.
Animals rarely solve problems spontaneously, yet certain bird species are able to rapidly gain access to food hung on the end of a long string, by repeatedly pulling and then stepping on the string. For over 400 years it has been a mystery as to how the birds spontaneously solve the “string pulling” problem.
The University of Auckland research shows that such problem solving is not created by birds first solving the problem in their heads. Rather, problem solving occurs online as the bird makes the food on the end of the string move.
“Crows and parrots have long been known to solve the string pulling problem immediately. What our new research shows is that these performances are due to the birds being able to react in the moment to the effects of their actions, rather than being able to mentally plan out their actions,” says Dr Alex Taylor, lead author on the study.
“Thus string pulling appears to be based on a different type of intelligence than we had thought. Instead of the crows using sophisticated cognitive software to model the world, it appears their neural hardware is sufficiently well connected and/or specialised for them to react to the effect of their actions immediately. This allows them to solve problems that other bird species cannot.”
The work, by Dr Taylor, Brenna Knaebe and Professor Russell Gray, titled “An end to insight? New Caledonian crows can spontaneously solve problems without planning their actions”, has been published in the Proceedings of the Royal Society B: Biological Sciences online.
Biofeedback-augmented video game helps children curb their anger
Often, when people talk about children and the psychological effects of playing video games, it’s nothing good – there are certainly plenty of individuals who maintain that if a child spends too much time blowing away virtual enemies, they will become more aggressive, antisocial people in the real world. A new game developed at Boston Children’s Hospital, however, is intended to do just the opposite. It helps children with anger problems to control their temper, so they’ll get along better with other people.
The game, appropriately called RAGE Control, requires the young player to shoot at enemy spaceships while sparing friendly ones. The child’s heart rate is monitored and displayed on the screen, via a sensor attached to one of their fingers. As long as they keep calm and their heart rate stays below a certain threshold, they can keep blasting at the spaceships. If they lose control and their heart rate goes too high, however, they lose the ability to shoot – the only way to regain that ability is to calm back down and lower their heart rate.
“The connections between the brain’s executive control centers and emotional centers are weak in people with severe anger problems,” said Dr. Joseph Gonzalez-Heydrich, co-creator of the game and senior investigator on the study. “However, to succeed at RAGE Control, players have to learn to use these centers at the same time to score points.”
Genes, depression and life satisfaction
Vulnerability to major depression is linked with how satisfied we are with our lives. This association is largely due to genes.
This is the main finding of a new twin study from the Norwegian Institute of Public Health in collaboration with the University of Oslo. The researchers compared longitudinal information from identical and fraternal twins to determine how vulnerability to major depression is associated with dispositional (overall) lifetime satisfaction.
Previous studies have systematically shown that life satisfaction is considerably stable over time. People who are satisfied at any one point in life are often also satisfied at other times in their lives. This stability—the dispositional life satisfaction—is often said to reflect an underlying positive mood or a positive disposition. Previous studies have also shown that people with such a positive disposition are less depressed, but very few studies have examined the mechanisms behind this relationship.
Results
• Both men and women who met the criteria for lifetime major depression (15.8% and 11.1% respectively) reported lower life satisfaction.
• 74% of the relationship between major depression and life satisfaction could be explained by genes.
• The remaining association (26%) could be explained by unique environmental factors.
• The researchers also calculated the heritability of dispositional life satisfaction and major depression separately. The heritability of dispositional life satisfaction, which has not previously been reported, was estimated to be 72%. In other words, it is largely genes that explain why we differ in our tendency to be satisfied and content with our lives.
• Major depression had a heritability of 34%, which is highly consistent with previous studies.
“The stable tendency to see the bright side of life is associated with lower risk of major depression because some genetic factors influence both conditions”, says researcher Ragnhild Bang Nes from the Division of Mental Health. Genes involved in satisfaction and positivity thus give protection against major depression. Nes is the main author of the study that was recently published in the Journal of Affective Disorders.
Susceptibility to both depression and overall life satisfaction is partly influenced by the same set of genes, but is also influenced by genes that are unique to each.
“The heritability figures mean that 72% of the individual differences in overall satisfaction, and 34% of the differences in depression, are caused by genes. These figures do not provide information on the importance of specific genes for an individual’s life satisfaction or risk of major depression. Traits and propensities like dispositional life satisfaction and vulnerability to major depression are not heritable in themselves. Heritability refers to the importance of genes for explaining the differences between people and the estimates may vary across time and place”, explains Nes.
Although the heritability of major depression was lower than that of life satisfaction, this does not necessarily mean that life satisfaction is far more heritable than depression. The researchers used questionnaire data from two time points to measure dispositional life satisfaction, and a single clinical interview to measure the prevalence of lifetime major depression. The use of only a single assessment to measure depression may partly explain why the heritability of depression is so much lower than life satisfaction.
Can we prevent depression by promoting life satisfaction?
“We found that depression and life satisfaction did not share as many environmental factors as genetic factors. This means that environmental factors of importance to life satisfaction (for example, activities and interventions that make you happy and content) only to a small extent protect against depression”, says Nes.
“Although our underlying disposition to life satisfaction and positivity appears to be relatively stable, small actions in our daily lives may provide temporary pleasures, and these are also important. How we spend our time is tremendously important for our happiness and well-being. It is therefore important to encourage and follow up on activities that make us happy”.
Nes adds:
“To some extent, positive experiences may also accumulate over time and create favorable conditions for our quality of life”.
(Source: fhi.no)
Can your body sense future events without any external clue?
Wouldn’t it be amazing if our bodies prepared us for future events that could be very important to us, even if there’s no clue about what those events will be?
Presentiment without any external clues may, in fact, exist, according to new Northwestern University research that analyzes the results of 26 studies published between 1978 and 2010.
Researchers already know that our subconscious minds sometimes know more than our conscious minds. Physiological measures of subconscious arousal, for instance, tend to show up before conscious awareness that a deck of cards is stacked against us.
"What hasn’t been clear is whether humans have the ability to predict future important events even without any clues as to what might happen," said Julia Mossbridge, lead author of the study and research associate in the Visual Perception, Cognition and Neuroscience Laboratory at Northwestern.
A person playing a video game at work while wearing headphones, for example, can’t hear when his or her boss is coming around the corner.
"But our analysis suggests that if you were tuned into your body, you might be able to detect these anticipatory changes between two and 10 seconds beforehand and close your video game," Mossbridge said. "You might even have a chance to open that spreadsheet you were supposed to be working on. And if you were lucky, you could do all this before your boss entered the room."
This phenomenon is sometimes called “presentiment,” as in “sensing the future,” but Mossbridge said she and other researchers are not sure whether people are really sensing the future.
"I like to call the phenomenon ‘anomalous anticipatory activity,’" she said. "The phenomenon is anomalous, some scientists argue, because we can’t explain it using present-day understanding about how biology works; though explanations related to recent quantum biological findings could potentially make sense. It’s anticipatory because it seems to predict future physiological changes in response to an important event without any known clues, and it’s an activity because it consists of changes in the cardiopulmonary, skin and nervous systems."
(Source: eurekalert.org)
Early Intervention Improves Social Skills and Brain Activity in Preschoolers with Autism
The Early Start Denver Model (ESDM), a comprehensive behavioral early intervention program that is appropriate for children with autism spectrum disorder (ASD) as young as 12 months, has been found to be effective in improving social skills and brain responses to social cues in a randomized controlled study published online today in the Journal of the American Academy of Child & Adolescent Psychiatry.
“So much of a toddler’s learning involves social interaction, and early intervention that promotes attention to people and social cues may pay dividends in promoting the normal development of the brain and behavior,” said Geraldine Dawson, Ph.D., Autism Speaks chief science officer and the study’s lead author. This is the first controlled study of an intensive early intervention that demonstrates both improvement of social skills and brain responses to social stimuli resulting from intensive early intervention. Given that the American Academy of Pediatrics recommends that all 18- and 24-month-old children be screened for autism, “it is vital that we have effective therapies available for young children as soon as they are diagnosed,” continued Dr. Dawson.
“This may be the first demonstration that a behavioral intervention for autism is associated with changes in brain function as well as positive changes in behavior,” said Thomas R. Insel, M.D., director of the National Institute of Mental Health. “By studying changes in the neural response to faces, Dawson and her colleagues have identified a new target and a potential biomarker that can guide treatment development.”
ESDM, which combines applied behavioral analysis (ABA) teaching methods with developmental ‘relationship-based’ approaches, was previously demonstrated to achieve significant gains in cognitive, language and daily living skills compared to children with ASD who received commonly available community interventions. On average, the preschoolers receiving ESDM for two years improved 17.5 standard score points compared to 7.0 points in the community intervention comparison group.