Posts tagged intelligence
Articles and news from the latest research reports.
New Studies Show Promise for Brain Training in Improving Fluid Intelligence
Whether computerized games designed by psychologists and neuroscientists can literally make people smarter has been hotly debated by scientists, with a small but outspoken cadre of skeptics demanding stronger proof. Now two new studies have found the kind of real-world benefits from the brain-training games that skeptics have been calling for.
The first, published today in the Proceedings of the National Academy of Sciences, found that less than six hours of brain games played over the course of 10 weeks enabled poor first-graders who attend school irregularly due to family problems to catch up with their regularly-attending peers in math and language grades.
The second, presented over the weekend at the Cognitive Neuroscience Society meeting in Boston, combined the results of 13 previous studies of computerized brain-training in young adults to conclude that training significantly enhances fluid intelligence—the fundamental human ability to detect patterns, reason, and learn. That is, practicing the games literally makes people smarter.
Together with other recent studies demonstrating real-world benefits of brain training in healthy older adults, preschoolers, and school children with ADHD, the new papers appear to provide fresh ammunition to psychologists and neuroscientists whose research has been under attack by a handful of skeptics who insist that the training is a waste of time.
Scientists identify gene linking brain structure to intelligence
For the first time, scientists at King’s College London have identified a gene linking the thickness of the grey matter in the brain to intelligence. The study is published today in Molecular Psychiatry and may help scientists understand biological mechanisms behind some forms of intellectual impairment.
The researchers looked at the cerebral cortex, the outermost layer of the human brain. It is known as ‘grey matter’ and plays a key role in memory, attention, perceptual awareness, thought, language and consciousness. Previous studies have shown that the thickness of the cerebral cortex, or ‘cortical thickness’, closely correlates with intellectual ability, however no genes had yet been identified.
An international team of scientists, led by King’s, analysed DNA samples and MRI scans from 1,583 healthy 14 year old teenagers, part of the IMAGEN cohort. The teenagers also underwent a series of tests to determine their verbal and non-verbal intelligence.
Dr Sylvane Desrivières, from the MRC Social, Genetic and Developmental Psychiatry Centre at King’s College London’s Institute of Psychiatry and lead author of the study, said: “We wanted to find out how structural differences in the brain relate to differences in intellectual ability. The genetic variation we identified is linked to synaptic plasticity – how neurons communicate. This may help us understand what happens at a neuronal level in certain forms of intellectual impairments, where the ability of the neurons to communicate effectively is somehow compromised.”
She adds: “It’s important to point out that intelligence is influenced by many genetic and environmental factors. The gene we identified only explains a tiny proportion of the differences in intellectual ability, so it’s by no means a ‘gene for intelligence’.”
The researchers looked at over 54,000 genetic variants possibly involved in brain development. They found that, on average, teenagers carrying a particular gene variant had a thinner cortex in the left cerebral hemisphere, particularly in the frontal and temporal lobes, and performed less well on tests for intellectual ability. The genetic variation affects the expression of the NPTN gene, which encodes a protein acting at neuronal synapses and therefore affects how brain cells communicate.
To confirm their findings, the researchers studied the NPTN gene in mouse and human brain cells. The researchers found that the NPTN gene had a different activity in the left and right hemispheres of the brain, which may cause the left hemisphere to be more sensitive to the effects of NPTN mutations. Their findings suggest that some differences in intellectual abilities can result from the decreased function of the NPTN gene in particular regions of the left brain hemisphere.
The genetic variation identified in this study only accounts for an estimated 0.5% of the total variation in intelligence. However, the findings may have important implications for the understanding of biological mechanisms underlying several psychiatric disorders, such as schizophrenia, autism, where impaired cognitive ability is a key feature of the disorder.
(Source: kcl.ac.uk)
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.”
Study finds crocodiles are cleverer than previously thought
Turns out the crocodile can be a shrewd hunter himself. A University of Tennessee, Knoxville, researcher has found that some crocodiles use lures to hunt their prey.
Vladimir Dinets, a research assistant professor in the Department of Psychology, is the first to observe two crocodilian species—muggers and American alligators—using twigs and sticks to lure birds, particularly during nest-building time.
The research is published in the current edition of Ethology, Ecology and Evolution. Dinets’ research is the first report of tool use by any reptiles, and also the first known case of predators timing the use of lures to a seasonal behavior of the prey—nest-building.
Dinets first observed the behavior in 2007 when he spotted crocodiles lying in shallow water along the edge of a pond in India with small sticks or twigs positioned across their snouts. The behavior potentially fooled nest-building birds wading in the water for sticks into thinking the sticks were floating on the water. The crocodiles remained still for hours and if a bird neared the stick, they would lunge.
To see if the stick-displaying was a form of clever predation, Dinets and his colleagues performed systematic observations of the reptiles for one year at four sites in Louisiana, including two rookery and two nonrookery sites. A rookery is a bird breeding ground. The researchers observed a significant increase in alligators displaying sticks on their snouts from March to May, the time birds were building nests. Specifically, the reptiles in rookeries had sticks on their snouts during and after the nest-building season. At non-rookery sites, the reptiles used lures during the nest-building season.
"This study changes the way crocodiles have historically been viewed," said Dinets. "They are typically seen as lethargic, stupid and boring but now they are known to exhibit flexible multimodal signaling, advanced parental care and highly coordinated group hunting tactics."
The observations could mean the behavior is more widespread within the reptilian group and could also shed light on how crocodiles’ extinct relatives—dinosaurs—behaved.
"Our research provides a surprising insight into previously unrecognized complexity of extinct reptile behavior," said Dinets. "These discoveries are interesting not just because they show how easy it is to underestimate the intelligence of even relatively familiar animals, but also because crocodilians are a sister taxon of dinosaurs and flying reptiles."
Dinets collaborated with J.C and J.D. Brueggen from the St. Augustine Alligator Farm Zoological Park in St. Augustine, Fla. More of his crocodile research can be found in his book “Dragon Songs.”
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.
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)
Breastfeeding Duration Appears Associated with Intelligence Later in Life
Breastfeeding longer is associated with better receptive language at 3 years of age and verbal and nonverbal intelligence at age 7 years, according to a study published by JAMA Pediatrics, a JAMA Network publication.
Evidence supports the relationship between breastfeeding and health benefits in infancy, but the extent to which breastfeeding leads to better cognitive development is less certain, according to the study background.
Mandy B. Belfort, M.D., M.P.H., of Boston Children’s Hospital, and colleagues examined the relationships of breastfeeding duration and exclusivity with child cognition at ages 3 and 7 years. They also studied the extent to which maternal fish intake during lactation affected associations of infant feeding and later cognition. Researchers used assessment tests to measure cognition.“Longer breastfeeding duration was associated with higher Peabody Picture Vocabulary Test score at age 3 years (0.21; 95% CI, 0.03-0.38 points per month breastfed) and with higher intelligence on the Kaufman Brief Intelligence Test at age 7 years (0.35; 0.16-0.53 verbal points per month breastfed; and 0.29; 0.05-0.54 nonverbal points per month breastfed),” according to the study results. However, the study also noted that breastfeeding duration was not associated with Wide Range Assessment of Memory and Learning scores.
As for fish intake (less than 2 servings per week vs. greater than or equal to 2 servings), the relationship between breastfeeding duration and the Wide Range Assessment of Visual Motor Abilities at 3 years of age appeared to be stronger in children of women with higher vs. lower fish intake, although this finding was not statistically significant, the results also indicate.
“In summary, our results support a causal relationship of breastfeeding in infancy with receptive language at age 3 and with verbal and nonverbal IQ at school age. These findings support national and international recommendations to promote exclusive breastfeeding through age 6 months and continuation of breastfeeding through at least age 1 year,” the authors conclude.
Breastfeeding and Cognition: Can IQ Tip the Scale?
In an editorial, Dimitri A. Christakis, M.D., M.P.H., of the Seattle Children’s Hospital Research Institute, writes: “The authors reported an IQ benefit at age 7 years from breastfeeding of 0.35 points per month on the verbal scale and 0.29 points per month on the nonverbal one. Put another way, breastfeeding an infant for the first year of life would be expected to increase his or her IQ by about four points or one-third of a standard deviation.”
“However, the problem currently is not so much that most women do not initiate breastfeeding, it is that they do not sustain it. In the United States about 70 percent of women overall initiate breastfeeding, although only 50 percent of African American women do. However, by six months, only 35 percent and 20 percent, respectively, are still breastfeeding,” Christakis continues.
“Furthermore, workplaces need to provide opportunities and spaces for mothers to use them. Fourth, breastfeeding in public should be destigmatized. Clever social media campaigns and high-quality public service announcements might help with that. As with lead, some of these actions may require legislative action either at the federal or state level. Let’s allow our children’s cognitive function be the force that tilts the scale, and let’s get on with it,” Christakis concludes.
Impulsive murderers much more mentally impaired than those who kill strategically
The minds of murderers who kill impulsively, often out of rage, and those who carefully carry out premeditated crimes differ markedly both psychologically and intellectually, according to a new study by Northwestern Medicine® researcher Robert Hanlon.
“Impulsive murderers were much more mentally impaired, particularly cognitively impaired, in terms of both their intelligence and other cognitive functions,” said Hanlon, senior author of the study and associate professor of clinical psychiatry and clinical neurology at Northwestern University Feinberg School of Medicine.
“The predatory and premeditated murderers did not typically show any major intellectual or cognitive impairments, but many more of them have psychiatric disorders,” he said.
Published online in the journal Criminal Justice and Behavior, the study is the first to examine the neuropsychological and intelligence differences of murderers who kill impulsively versus those who kill as the result of a premeditated strategic plan.
- Compared to impulsive murderers, premeditated murderers are almost twice as likely to have a history of mood disorders or psychotic disorders — 61 percent versus 34 percent.
- Compared to predatory murderers, impulsive murderers are more likely to be developmentally disabled and have cognitive and intellectual impairments — 59 percent versus 36 percent.
- Nearly all of the impulsive murderers have a history of alcohol or drug abuse and/or were intoxicated at the time of the crime — 93 percent versus 76 percent of those who strategized about their crimes.
Based on established criteria, 77 murderers from typical prison populations in Illinois and Missouri were classified into the two groups (affective/impulsive and premeditated/predatory murderers). Hanlon compared their performances on standardized measures of intelligence and neuropsychological tests of memory, attention and executive functions. He spent hours with each individual, administering series of tests to complete an evaluation. Hanlon has spent thousands of hours studying the minds of murderers through his research.
“It’s important to try to learn as much as we can about the thought patterns and the psychopathology, neuropathology and mental disorders that tend to characterize the types of people committing these crimes,” he said. “Ultimately, we may be able to increase our rates of prevention and also assist the courts, particularly helping judges and juries be more informed about the minds and the mental abnormalities of the people who commit these violent crimes.”
(Image: ALAMY)
IQ link to baby’s weight gain in first month
New research from the University of Adelaide shows that weight gain and increased head size in the first month of a baby’s life is linked to a higher IQ at early school age.
The study was led by University of Adelaide Public Health researchers, who analysed data from more than 13,800 children who were born full-term.
The results, published today in the international journal Pediatrics, show that babies who put on 40% of their birthweight in the first four weeks had an IQ 1.5 points higher by the time they were six years of age, compared with babies who only put on 15% of their birthweight.
Those with the biggest growth in head circumference also had the highest IQs.
"Head circumference is an indicator of brain volume, so a greater increase in head circumference in a newborn baby suggests more rapid brain growth," says the lead author of the study, Dr Lisa Smithers from the University of Adelaide’s School of Population Health.
"Overall, newborn children who grew faster in the first four weeks had higher IQ scores later in life," she says.
"Those children who gained the most weight scored especially high on verbal IQ at age 6. This may be because the neural structures for verbal IQ develop earlier in life, which means the rapid weight gain during that neonatal period could be having a direct cognitive benefit for the child."
Previous studies have shown the association between early postnatal diet and IQ, but this is the first study of its kind to focus on the IQ benefits of rapid weight gain in the first month of life for healthy newborn babies.
Dr Smithers says the study further highlights the need for successful feeding of newborn babies.
"We know that many mothers have difficulty establishing breastfeeding in the first weeks of their baby’s life," Dr Smithers says.
"The findings of our study suggest that if infants are having feeding problems, there needs to be early intervention in the management of that feeding."
(Image: thebabypicz.com)
Blood Vessels in the Eye Linked With IQ, Cognitive Function
The width of blood vessels in the retina, located at the back of the eye, may indicate brain health years before the onset of dementia and other deficits, according to a new study published in Psychological Science, a journal of the Association for Psychological Science.
Research shows that younger people who score low on intelligence tests, such as IQ, tend to be at higher risk for poorer health and shorter lifespan, but factors like socioeconomic status and health behaviors don’t fully account for the relationship. Psychological scientist Idan Shalev of Duke University and colleagues wondered whether intelligence might serve as a marker indicating the health of the brain, and specifically the health of the system of blood vessels that provides oxygen and nutrients to the brain.
To investigate the potential link between intelligence and brain health, the researchers borrowed a technology from a somewhat unexpected domain: ophthalmology.
Shalev and colleagues used digital retinal imaging, a relatively new and noninvasive method, to gain a window onto vascular conditions in the brain by looking at the small blood vessels of the retina, located at the back of the eye. Retinal blood vessels share similar size, structure, and function with blood vessels in the brain and can provide a way of examining brain health in living humans.
The researchers examined data from participants taking part in the Dunedin Multidisciplinary Health and Development Study, a longitudinal investigation of health and behavior in over 1000 people born between April 1972 and March 1973 in Dunedin, New Zealand.
The results were intriguing.
Having wider retinal venules was linked with lower IQ scores at age 38, even after the researchers accounted for various health, lifestyle, and environmental risk factors that might have played a role.
Individuals who had wider retinal venules showed evidence of general cognitive deficits, with lower scores on numerous measures of neurospsychological functioning, including verbal comprehension, perceptual reasoning, working memory, and executive function.
Surprisingly, the data revealed that people who had wider venules at age 38 also had lower IQ in childhood, a full 25 years earlier.
It’s “remarkable that venular caliber in the eye is related, however modestly, to mental test scores of individuals in their 30s, and even to IQ scores in childhood,” the researchers observe.
The findings suggest that the processes linking vascular health and cognitive functioning begin much earlier than previously assumed, years before the onset of dementia and other age-related declines in brain functioning.
“Digital retinal imaging is a tool that is being used today mainly by eye doctors to study diseases of the eye,” Shalev notes. “But our initial findings indicate that it may be a useful investigative tool for psychological scientists who want to study the link between intelligence and health across the lifespan.”
The current study doesn’t address the specific mechanisms that drive the relationship between retinal vessels and cognitive functioning, but the researchers surmise that it may have to do with oxygen supply to the brain.
“Increasing knowledge about retinal vessels may enable scientists to develop better diagnosis and treatments to increase the levels of oxygen into the brain and by that, to prevent age-related worsening of cognitive abilities,” they conclude.