Posts tagged cognition
Articles and news from the latest research reports.
Your Brain Is Fine-Tuning Its Wiring Throughout Your Life
The white matter microstructure, the communication pathways of the brain, continues to develop/mature as one ages. Studies link age-related differences in white matter microstructure to specific cognitive abilities in childhood and adulthood.
Most prior studies, however, did not include individuals from the entire life span or evaluated a limited section of white matter tracts. This knowledge gap prompted a new study published this week in Biological Psychiatry.
Dr. Bart Peters, of the Zucker Hillside Hospital, and his colleagues investigated the relationship of age and neurocognitive performance to nine white matter tracts from childhood to late adulthood.
To accomplish this, they recruited 296 healthy volunteers who ranged from 8 to 68 years of age. The participants completed a comprehensive battery of tests designed to measure their cognitive functioning, including speed, attention, memory, and learning. They also underwent a non-invasive diffusion tensor imaging scan, a technology that allowed the researchers to create maps of the 9 major white matter tracts under investigation.
The combination of this data allowed them to identify the neurocognitive correlates of each white matter tract in relation to its unique aging pattern.
They found that, from childhood into early adulthood, differences in fractional anisotropy – a measure of connectivity – of the cingulum were associated with executive functioning, whereas fractional anisotropy of the inferior fronto-occipital fasciculus was associated with visual learning and global cognitive performance via speed of processing.
"Our study identified key brain circuits that develop during adolescence and young adulthood that are associated with the growth of learning, memory and planning abilities. These findings suggest that young people may not have full capacity of these functions until these connections have completed their normal trajectory of maturation beyond adolescence," explained Peters.
"Our brain is changing throughout our lives. These changes underlie the capacities that emerge and are refined through adulthood," commented Dr. John Krystal, Editor of Biological Psychiatry. “There are clues that the steps that we take to preserve our medical health and stimulate our minds also serve to further refine and maintain these connections. For good reasons, attending to brain health is increasingly a focus of healthy aging.”
In addition, many individuals diagnosed with psychiatric disorders suffer with neurocognitive dysfunction as part of their illness, which is particularly difficult to alleviate with currently available treatments. Studies such as this may help to identify specific brain circuits/pathways that could serve as potential targets for treatment interventions.
What makes us human? Unique brain area linked to higher cognitive powers
Oxford University researchers have identified an area of the human brain that appears unlike anything in the brains of some of our closest relatives.
The brain area pinpointed is known to be intimately involved in some of the most advanced planning and decision-making processes that we think of as being especially human.
'We tend to think that being able to plan into the future, be flexible in our approach and learn from others are things that are particularly impressive about humans. We've identified an area of the brain that appears to be uniquely human and is likely to have something to do with these cognitive powers,' says senior researcher Professor Matthew Rushworth of Oxford University's Department of Experimental Psychology.
MRI imaging of 25 adult volunteers was used to identify key components in the ventrolateral frontal cortex area of the human brain, and how these components were connected up with other brain areas. The results were then compared to equivalent MRI data from 25 macaque monkeys.
Children get plenty of benefits from music lessons. Learning to play instruments can fuel their creativity, and practicing can teach much-needed focus and discipline. And the payoff, whether in learning a new song or just mastering a chord, often boosts self-esteem.
But Harvard researchers now say that one oft-cited benefit — that studying music improves intelligence — is a myth.
Though it has been embraced by everyone from advocates for arts education to parents hoping to encourage their kids to stick with piano lessons, a pair of studies conducted by Samuel Mehr, a Harvard Graduate School of Education (HGSE) doctoral student working in the lab of Elizabeth Spelke, the Marshall L. Berkman Professor of Psychology, found that music training had no effect on the cognitive abilities of young children. The studies are described in a Dec. 11 paper published in the open-access journal PLoS One.
“More than 80 percent of American adults think that music improves children’s grades or intelligence,” Mehr said. “Even in the scientific community, there’s a general belief that music is important for these extrinsic reasons. But there is very little evidence supporting the idea that music classes enhance children’s cognitive development.”
The notion that music training can make someone smarter, Mehr said, can largely be traced to a single study published in Nature. In it, researchers identified what they called the “Mozart effect.” After listening to music, test subjects performed better on spatial tasks.
Though the study was later debunked, the notion that simply listening to music could make someone smarter became firmly embedded in the public imagination, and spurred a host of follow-up studies, including several that focused on the cognitive benefits of music lessons.
Though dozens of studies have explored whether and how music and cognitive skills might be connected, when Mehr and colleagues reviewed the literature they found only five studies that used randomized trials, the gold standard for determining causal effects of educational interventions on child development. Of the five, only one showed an unambiguously positive effect, and it was so small — just a 2.7 point increase in IQ after a year of music lessons — that it was barely enough to be statistically significant.
“The experimental work on this question is very much in its infancy, but the few published studies on the topic show little evidence for ‘music makes you smarter,’” Mehr said.
To explore the connection between music and cognition, Mehr and his colleagues recruited 29 parents and 4-year-old children from the Cambridge area. After initial vocabulary tests for the children and music aptitude tests for the parents, each was randomly assigned to one of two classes, one that had music training, or another that focused on visual arts.
“We wanted to test the effects of the type of music education that actually happens in the real world, and we wanted to study the effect in young children, so we implemented a parent-child music enrichment program with preschoolers,” Mehr said. “The goal is to encourage musical play between parents and children in a classroom environment, which gives parents a strong repertoire of musical activities they can continue to use at home with their kids.”
Among the key changes Mehr and his colleagues made from earlier studies were controlling for the effect of different teachers — Mehr taught both the music and visual arts classes — and using assessment tools designed to test areas of cognition, vocabulary, mathematics, and two spatial tasks.
“Instead of using something general, like an IQ test, we tested four specific domains of cognition,” Mehr said. “If there really is an effect of music training on children’s cognition, we should be able to better detect it here than in previous studies, because these tests are more sensitive than tests of general intelligence.”
The study’s results, however, showed no evidence for cognitive benefits of music training.
While the groups performed comparably on vocabulary and number-estimation tasks, the assessments showed that children who received music training performed slightly better at one spatial task, while those who received visual arts training performed better at the other.
“Study One was very small. We only had 15 children in the music group, and 14 in the visual arts,” Mehr said. “The effects were tiny, and their statistical significance was marginal at best. So we attempted to replicate the study, something that hasn’t been done in any of the previous work.”
To replicate the effect, Mehr and colleagues designed a second study that recruited 45 parents and children, half of whom received music training, and half of whom received no training.
Just as in the first study, Mehr said, there was no evidence that music training offered any cognitive benefit. Even when the results of both studies were pooled to allow researchers to compare the effect of music training, visual arts training, and no training, there was no sign that any group outperformed the others.
“There were slight differences in performance between the groups, but none were large enough to be statistically significant,” Mehr said. “Even when we used the finest-grained statistical analyses available to us, the effects just weren’t there.”
While the results suggest studying music may not be a shortcut to educational success, Mehr said there is still substantial value in music education.
“There’s a compelling case to be made for teaching music that has nothing to do with extrinsic benefits,” he said. “We don’t teach kids Shakespeare because we think it will help them do better on the SATs. We do it because we believe Shakespeare is important.
“Music is an ancient, uniquely human activity. The oldest flutes that have been dug up are 40,000 years old, and human song long preceded that,” he said. “Every single culture in the world has music, including music for children. Music says something about what it means to be human, and it would be crazy not to teach this to our children.”
Even when test scores go up, some cognitive abilities don’t
To evaluate school quality, states require students to take standardized tests; in many cases, passing those tests is necessary to receive a high-school diploma. These high-stakes tests have also been shown to predict students’ future educational attainment and adult employment and income.
Such tests are designed to measure the knowledge and skills that students have acquired in school — what psychologists call “crystallized intelligence.” However, schools whose students have the highest gains on test scores do not produce similar gains in “fluid intelligence” — the ability to analyze abstract problems and think logically — according to a new study from MIT neuroscientists working with education researchers at Harvard University and Brown University.
In a study of nearly 1,400 eighth-graders in the Boston public school system, the researchers found that some schools have successfully raised their students’ scores on the Massachusetts Comprehensive Assessment System (MCAS). However, those schools had almost no effect on students’ performance on tests of fluid intelligence skills, such as working memory capacity, speed of information processing, and ability to solve abstract problems.
“Our original question was this: If you have a school that’s effectively helping kids from lower socioeconomic environments by moving up their scores and improving their chances to go to college, then are those changes accompanied by gains in additional cognitive skills?” says John Gabrieli, the Grover M. Hermann Professor of Health Sciences and Technology, professor of brain and cognitive sciences, and senior author of a forthcoming Psychological Science paper describing the findings.
Instead, the researchers found that educational practices designed to raise knowledge and boost test scores do not improve fluid intelligence. “It doesn’t seem like you get these skills for free in the way that you might hope, just by doing a lot of studying and being a good student,” says Gabrieli, who is also a member of MIT’s McGovern Institute for Brain Research.
Measuring cognition
This study grew out of a larger effort to find measures beyond standardized tests that can predict long-term success for students. “As we started that study, it struck us that there’s been surprisingly little evaluation of different kinds of cognitive abilities and how they relate to educational outcomes,” Gabrieli says.
The data for the Psychological Science study came from students attending traditional, charter, and exam schools in Boston. Some of those schools have had great success improving their students’ MCAS scores — a boost that studies have found also translates to better performance on the SAT and Advanced Placement tests.
The researchers calculated how much of the variation in MCAS scores was due to the school that students attended. For MCAS scores in English, schools accounted for 24 percent of the variation, and they accounted for 34 percent of the math MCAS variation. However, the schools accounted for very little of the variation in fluid cognitive skills — less than 3 percent for all three skills combined.
In one example of a test of fluid reasoning, students were asked to choose which of six pictures completed the missing pieces of a puzzle — a task requiring integration of information such as shape, pattern, and orientation.
“It’s not always clear what dimensions you have to pay attention to get the problem correct. That’s why we call it fluid, because it’s the application of reasoning skills in novel contexts,” says Amy Finn, an MIT postdoc and lead author of the paper.
Even stronger evidence came from a comparison of about 200 students who had entered a lottery for admittance to a handful of Boston’s oversubscribed charter schools, many of which achieve strong improvement in MCAS scores. The researchers found that students who were randomly selected to attend high-performing charter schools did significantly better on the math MCAS than those who were not chosen, but there was no corresponding increase in fluid intelligence scores.
However, the researchers say their study is not about comparing charter schools and district schools. Rather, the study showed that while schools of both types varied in their impact on test scores, they did not vary in their impact on fluid cognitive skills.
The researchers plan to continue tracking these students, who are now in 10th grade, to see how their academic performance and other life outcomes evolve. They have also begun to participate in a new study of high school seniors to track how their standardized test scores and cognitive abilities influence their rates of college attendance and graduation.
Implications for education
Gabrieli notes that the study should not be interpreted as critical of schools that are improving their students’ MCAS scores. “It’s valuable to push up the crystallized abilities, because if you can do more math, if you can read a paragraph and answer comprehension questions, all those things are positive,” he says.
He hopes that the findings will encourage educational policymakers to consider adding practices that enhance cognitive skills. Although many studies have shown that students’ fluid cognitive skills predict their academic performance, such skills are seldom explicitly taught.
“Schools can improve crystallized abilities, and now it might be a priority to see if there are some methods for enhancing the fluid ones as well,” Gabrieli says.
Some studies have found that educational programs that focus on improving memory, attention, executive function, and inductive reasoning can boost fluid intelligence, but there is still much disagreement over what programs are consistently effective.
(Source: web.mit.edu)
Study Suggests Low Vitamin D Causes Damage to Brain
A new study led by University of Kentucky researchers suggests that a diet low in vitamin D causes damage to the brain.
In addition to being essential for maintaining bone health, newer evidence shows that vitamin D serves important roles in other organs and tissue, including the brain. Published in Free Radical Biology and Medicine, the UK study showed that middle-aged rats that were fed a diet low in vitamin D for several months developed free radical damage to the brain, and many different brain proteins were damaged as identified by redox proteomics. These rats also showed a significant decrease in cognitive performance on tests of learning and memory.
"Given that vitamin D deficiency is especially widespread among the elderly, we investigated how during aging from middle-age to old-age how low vitamin D affected the oxidative status of the brain," said lead author on the paper Allan Butterfield, professor in the UK Department of Chemistry, director of the Center of Membrane Sciences, faculty of Sanders-Brown Center on Aging, and director of the Free Radical Biology in Cancer Core of the Markey Cancer Center. “Adequate vitamin D serum levels are necessary to prevent free radical damage in brain and subsequent deleterious consequences."
Previously, low levels of vitamin D have been associated with Alzheimer’s disease, and it’s also been linked to the development of certain cancers and heart disease. In both the developed world and in areas of economic hardship where food intake is not always the most nutritious, vitamin D levels in humans are often low, particularly in the elderly population. Butterfield recommends persons consult their physicians to have their vitamin D levels determined, and if low that they eat foods rich in vitamin D, take vitamin D supplements, and/or get at least 10-15 minutes of sun exposure each day to ensure that vitamin D levels are normalized and remain so to help protect the brain.
(Source: uknow.uky.edu)
Brain Connectivity Study Reveals Striking Differences Between Men and Women
A new brain connectivity study from Penn Medicine published today in the Proceedings of National Academy of Sciences found striking differences in the neural wiring of men and women that’s lending credence to some commonly-held beliefs about their behavior.
In one of the largest studies looking at the “connectomes” of the sexes, Ragini Verma, PhD, an associate professor in the department of Radiology at the Perelman School of Medicine at the University of Pennsylvania, and colleagues found greater neural connectivity from front to back and within one hemisphere in males, suggesting their brains are structured to facilitate connectivity between perception and coordinated action. In contrast, in females, the wiring goes between the left and right hemispheres, suggesting that they facilitate communication between the analytical and intuition.
“These maps show us a stark difference—and complementarity—in the architecture of the human brain that helps provide a potential neural basis as to why men excel at certain tasks, and women at others,” said Verma.
For instance, on average, men are more likely better at learning and performing a single task at hand, like cycling or navigating directions, whereas women have superior memory and social cognition skills, making them more equipped for multitasking and creating solutions that work for a group. They have a mentalistic approach, so to speak.
Past studies have shown sex differences in the brain, but the neural wiring connecting regions across the whole brain that have been tied to such cognitive skills has never been fully shown in a large population.
In the study, Verma and colleagues, including co-authors Ruben C. Gur, PhD, a professor of psychology in the department of Psychiatry, and Raquel E. Gur, MD, PhD, professor of Psychiatry, Neurology and Radiology, investigated the gender-specific differences in brain connectivity during the course of development in 949 individuals (521 females and 428 males) aged 8 to 22 years using diffusion tensor imaging (DTI). DTI is water-based imaging technique that can trace and highlight the fiber pathways connecting the different regions of the brain, laying the foundation for a structural connectome or network of the whole brain.
This sample of youths was studied as part of the Philadelphia Neurodevelopmental Cohort, a National Institute of Mental Health-funded collaboration between the University of Pennsylvania Brain Behavior Laboratory and the Center for Applied Genomics at the Children’s Hospital of Philadelphia.
The brain is a roadmap of neural pathways linking many networks that help us process information and react accordingly, with behavior controlled by several of these sub-networks working in conjunction.
In the study, the researchers found that females displayed greater connectivity in the supratentorial region, which contains the cerebrum, the largest part of the brain, between the left and right hemispheres. Males, on the other hand, displayed greater connectivity within each hemisphere.
By contrast, the opposite prevailed in the cerebellum, the part of the brain that plays a major role in motor control, where males displayed greater inter-hemispheric connectivity and females displayed greater intra-hemispheric connectivity.
These connections likely give men an efficient system for coordinated action, where the cerebellum and cortex participate in bridging between perceptual experiences in the back of the brain, and action, in the front of the brain, according to the authors. The female connections likely facilitate integration of the analytic and sequential processing modes of the left hemisphere with the spatial, intuitive information processing modes of the right side.
The authors observed only a few gender differences in the connectivity in children younger than 13 years, but the differences were more pronounced in adolescents aged 14 to 17 years and young adults older than 17.
The findings were also consistent with a Penn behavior study, of which this imaging study was a subset of, that demonstrated pronounced sexual differences. Females outperformed males on attention, word and face memory, and social cognition tests. Males performed better on spatial processing and sensorimotor speed. Those differences were most pronounced in the 12 to 14 age range.
“It’s quite striking how complementary the brains of women and men really are,” said Dr. Ruben Gur. “Detailed connectome maps of the brain will not only help us better understand the differences between how men and women think, but it will also give us more insight into the roots of neurological disorders, which are often sex related.”
Next steps are to quantify how an individual’s neural connections are different from the population; identify which neural connections are gender specific and common in both; and to see if findings from functional magnetic resonance imaging (fMRI) studies fall in line with the connectome data.
Eat crow if you think I’m a bird-brain
Scientists have long suspected that corvids – the family of birds including ravens, crows and magpies – are highly intelligent. Now, Tübingen neurobiologists Lena Veit und Professor Andreas Nieder have demonstrated how the brains of crows produce intelligent behavior when the birds have to make strategic decisions. Their results are published in the latest edition of Nature Communications.
Crows are no bird-brains. Behavioral biologists have even called them “feathered primates” because the birds make and use tools, are able to remember large numbers of feeding sites, and plan their social behavior according to what other members of their group do. This high level of intelligence might seem surprising because birds’ brains are constructed in a fundamentally different way from those of mammals, including primates – which are usually used to investigate these behaviors.
The Tübingen researchers are the first to investigate the brain physiology of crows’ intelligent behavior. They trained crows to carry out memory tests on a computer. The crows were shown an image and had to remember it. Shortly afterwards, they had to select one of two test images on a touchscreen with their beaks based on a switching behavioral rules. One of the test images was identical to the first image, the other different. Sometimes the rule of the game was to select the same image, and sometimes it was to select the different one. The crows were able to carry out both tasks and to switch between them as appropriate. That demonstrates a high level of concentration and mental flexibility which few animal species can manage – and which is an effort even for humans.
The crows were quickly able to carry out these tasks even when given new sets of images. The researchers observed neuronal activity in the nidopallium caudolaterale, a brain region associated with the highest levels of cognition in birds. One group of nerve cells responded exclusively when the crows had to choose the same image – while another group of cells always responded when they were operating on the “different image” rule. By observing this cell activity, the researchers were often able to predict which rule the crow was following even before it made its choice.
The study published in Nature Communications provides valuable insights into the parallel evolution of intelligent behavior. “Many functions are realized differently in birds because a long evolutionary history separates us from these direct descendants of the dinosaurs,” says Lena Veit. “This means that bird brains can show us an alternative solution out of how intelligent behavior is produced with a different anatomy.” Crows and primates have different brains, but the cells regulating decision-making are very similar. They represent a general principle which has re-emerged throughout the history of evolution. “Just as we can draw valid conclusions on aerodynamics from a comparison of the very differently constructed wings of birds and bats, here we are able to draw conclusions about how the brain works by investigating the functional similarities and differences of the relevant brain areas in avian and mammalian brains,” says Professor Andreas Nieder.
Most songbirds learn their songs from an adult model, mostly from the father. However, there are relatively large differences in the accuracy how these songs are copied. Researchers from the Max Planck Institute for Ornithology in Seewiesen now found in juvenile zebra finches a possible mechanism that is responsible for the differences in the intensity of song learning. They provided the nerve growth factor “BDNF” to the song control system in the brain. With this treatment the learning ability in juvenile males could be enhanced in such a way that they were able to copy the songs of the father as good as it had been observed in the best learners in a zebra finch nest.
The improvement of cognitive abilities plays an important role in the therapy of neurological and psychiatric diseases. In this context research focusses more and more on the protein BDNF (Brain Derived Neurotrophic Factor). BDNF is mainly responsible for the preservation, growth and differentiation of nerve cells. Moreover, from experiments in mice it is known that BDNF enhances the ability to solve complex cognitive tasks.
In a learning experiment with zebra finches, researchers from the Max Planck Institute for Ornithology in Seewiesen in collaboration with scientists from the Free University of Amsterdam could now show for the first time in songbirds that BDNF acts as cognitive enhancer. They investigated zebra finch brother pairs that grew up with their genetic parents. In this setup juvenile birds will readily learn the songs from their fathers. However there are differences in the intensity of song learning among siblings of the same age. The worst learners have only a similarity of 20% with their fathers’ songs, whereas the best learners copy almost the entire songs of their fathers.
By now knowing the normal distribution of the learned songs within a zebra finch nest, as a next step the researchers were able to investigate the impact of BDNF on song learning. In one of the two brothers they enhanced the expression of BDNF in the song control system in the brain while the other brother did not get such a treatment. By analysing the songs the researchers found that those sons that received more BDNF had a higher similarity with the song of their fathers compared to normally reared juveniles. Remarkably, the learning efficiency in the BDNF-treated birds was as high as it has been previously observed in the best learners within the nest. This was due to an earlier onset of syllable copying in BDNF-treated birds and these birds also copied more and sang fewer improvised syllables. Therefore it is likely that the presence of BDNF in the song control system could correct possible inaccuracies in the song learning process, state the scientists around Manfred Gahr, who is the senior author of the study.
Primate brain development follows a predictable pattern
In a breakthrough for understanding brain evolution, neuroscientists have shown that differences between primate brains - from the tiny marmoset to human – can be largely explained as consequences of the same genetic program.
In research published in the Journal of Neuroscience, Professor Marcello Rosa and his team at Monash University’s School of Biomedical Sciences and colleagues at Universidade Federal do Rio de Janeiro, in Brazil, used computer modelling to demonstrate that the substantial enlargement of some areas of the human brain, vital to advanced cognition, reflected a consistent pattern that is seen across primate species of all sizes.
This finding suggests how the neural circuits responsible for traits that we consider uniquely human – such as the ability to plan, make complex decisions and speak – could have emerged simply as a natural consequence of the evolution of larger brains.
“We have known for a long time that certain areas of the human brain are much larger than one would expect based on how monkey brains are organised,” Professor Rosa said.
“What no one had realised is that this selective enlargement is part of a trend that has been present since the dawn of primates.”
Using publicly available brain maps, MRI imaging data and modelling software, the neuroscientists compared the sizes of different brain areasin humans and three monkey species: marmosets, capuchins and macaques. They found that two regions, the lateral prefrontal cortex and the temporal parietal junction, expand disproportionally to the rest of the brain.
The prefrontal cortex is related to long term planning, personality expression, decision-making, and behaviour modification. The temporal parietal junction is related to self-awareness and self-other distinction.
Lead author Tristan Chaplin, from the Department of Physiology will commence his PhD next year. He said the findings showed that those areas of the brain grew disproportionately in a predictable way.
“We found that the larger the brain is, the larger these areas get,” Tristan said.
“When you go from a small to big monkey - the marmoset to macaque - the prefrontal cortex and temporal parietal junction get larger relative to the rest of the cortex, and we see the same thing again when you compare macaques to humans.”
“This trend argues against the view that specific human mutations gave us these larger areas and advanced cognition and behaviour, but are a consequence of what happens in development when you grow a larger brain,” Tristan said.
Professor Rosa said the pattern held for primate species that evolved completely separately.
"If you compare the capuchin of South America and the macaque of Asia, their brains are almost identical, although they developed on opposite sides of the world. They both reflect the genetic plan of how a primate brain grows," Professor Rosa said.
This is the first computational comparative study conducted across several primate species. Tristan now hopes, in collaboration with zoos, to check if our closest primate relatives, the chimpanzees and gorillas, also have brain areas organised as his theory predicts.
(Source: monash.edu.au)
Genetic Influences on Cognition Increase with Age
About 70 percent of a person’s intelligence can be explained by their DNA — and those genetic influences only get stronger with age, according to new research from The University of Texas at Austin.
The study, authored by psychology researchers Elliot Tucker-Drob, Daniel Briley and Paige Harden, shows how genes can be stimulated or suppressed depending on the child’s environment and could help bridge the achievement gap between rich and poor students. The findings are published online in Current Directions in Psychological Science.
To investigate the underlying mechanisms at work, Tucker-Drob and his colleagues analyzed data from several studies tracking the cognitive ability and environmental circumstances of twin and sibling pairs. According to the findings, genetic factors account for 80 percent of cognition for children in economically advantaged households. Yet disadvantaged children – who rank lower in cognitive performance across the board – show almost no progress attributable to their genetic makeup.
This doesn’t mean disadvantaged children are genetically inferior. Instead, they have less high-quality opportunities, such as learning resources and parental involvement, to reach their genetic potential, Tucker-Drob says.
“Genetic influences on cognitive ability are maximized when people are free to select their own learning experiences,” says Tucker-Drob, who is an assistant professor of psychology. “We were born with blueprints; the question is how are we using our experiences to build upon our genetic makeup?”
In a related study, Daniel Briley, a psychology doctoral student, examined how genetic and environmental influences on cognition change over time. Using meta-analytic procedures — the statistical methods used to analyze and combine results from previous, related literature — Briley examined genetic and environmental influences on cognition in twin and sibling pairs from infancy to adolescence.
According to his findings, published in the July issue of Psychological Science, genes influencing cognition become activated during the first decade of life and accelerate over time. The results emphasize the importance of early literacy and education during the first decade of life.
“As children get older, their parents and teachers give them increasing autonomy to do their homework to the best of their ability, pay attention in class, and choose their peer group,” says Briley. “Each of these behaviors likely influences their academic development. If these types of behaviors are influenced by genes, then it would explain why the heritability of cognitive ability increases as children age.”
Tucker-Drob says this research highlights the possibilities for bridging the achievement gap between the rich and poor.
“The conventional view is that genes place an upper limit on the effects of social intervention on cognitive development,” says Tucker-Drob. “This research suggests the opposite. As social, educational and economic opportunities increase in a society, more children will have access to the resources they need to maximize their genetic potentials.”
(Source: utexas.edu)