1. Study suggests blood vessels in eye linked with IQ, cognitive function

    June 9, 2013 by Ashley

    From the Association for Psychological Science press release:

    senior man visionThe 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.

     

     


  2. Study suggests IQ predicted by ability to filter motion

    May 27, 2013 by Ashley

    From the University of Rochester press release via EurekAlert!:

    mind mazeA brief visual task can predict IQ, according to a new study.

    This surprisingly simple exercise measures the brain’s unconscious ability to filter out visual movement. The study shows that individuals whose brains are better at automatically suppressing background motion perform better on standard measures of intelligence.

    The test is the first purely sensory assessment to be strongly correlated with IQ and may provide a non-verbal and culturally unbiased tool for scientists seeking to understand neural processes associated with general intelligence.

    “Because intelligence is such a broad construct, you can’t really track it back to one part of the brain,” says Duje Tadin, a senior author on the study and an assistant professor of brain and cognitive sciences at the University of Rochester. “But since this task is so simple and so closely linked to IQ, it may give us clues about what makes a brain more efficient, and, consequently, more intelligent.”

    The unexpected link between IQ and motion filtering was reported online in the Cell Press journal Current Biology on May 23 by a research team lead by Tadin and Michael Melnick, a doctoral candidate in brain and cognitive sciences at the University of Rochester.

    In the study, individuals watched brief video clips of black and white bars moving across a computer screen. Their sole task was to identify which direction the bars drifted: to the right or to the left. The bars were presented in three sizes, with the smallest version restricted to the central circle where human motion perception is known to be optimal, an area roughly the width of the thumb when the hand is extended. Participants also took a standardized intelligence test.

    As expected, people with higher IQ scores were faster at catching the movement of the bars when observing the smallest image. The results support prior research showing that individuals with higher IQs make simple perceptual judgments swifter and have faster reflexes. “Being ‘quick witted’ and ‘quick on the draw’ generally go hand in hand,” says Melnick.

    But the tables turned when presented with the larger images. The higher a person’s IQ, the slower they were at detecting movement. “From previous research, we expected that all participants would be worse at detecting the movement of large images, but high IQ individuals were much, much worse,” says Melnick. That counter-intuitive inability to perceive large moving images is a perceptual marker for the brain’s ability to suppress background motion, the authors explain. In most scenarios, background movement is less important than small moving objects in the foreground. Think about driving in a car, walking down a hall, or even just moving your eyes across the room. The background is constantly in motion.

    The key discovery in this study is how closely this natural filtering ability is linked to IQ. The first experiment found a 64 percent correlation between motion suppression and IQ scores, a much stronger relationship than other sensory measures to date. For example, research on the relationship between intelligence and color discrimination, sensitivity to pitch, and reaction times have found only a 20 to 40 percent correlation. “In our first experiment, the effect for motion was so strong,” recalls Tadin, “that I really thought this was a fluke.”

    So the group tried to disprove the findings from the initial 12-participant study conducted while Tadin was at Vanderbilt University working with co-author Sohee Park, a professor of psychology. They reran the experiment at the University of Rochester on a new cohort of 53 subjects, administering the full IQ test instead of an abbreviated version and the results were even stronger; correlation rose to 71 percent. The authors also tested for other possible explanations for their findings.

    For example, did the surprising link to IQ simply reflect a person’s willful decision to focus on small moving images? To rule out the effect of attention, the second round of experiments randomly ordered the different image sizes and tested other types of large images that have been shown not to elicit suppression. High IQ individuals continued to be quicker on all tasks, except the ones that isolated motion suppression. The authors concluded that high IQ is associated with automatic filtering of background motion.

    “We know from prior research which parts of the brain are involved in visual suppression of background motion. This new link to intelligence provides a good target for looking at what is different about the neural processing, what’s different about the neurochemistry, what’s different about the neurotransmitters of people with different IQs,” says Tadin.

    The relationship between IQ and motion suppression points to the fundamental cognitive processes that underlie intelligence, the authors write. The brain is bombarded by an overwhelming amount of sensory information, and its efficiency is built not only on how quickly our neural networks process these signals, but also on how good they are at suppressing less meaningful information. “Rapid processing is of little utility unless it is restricted to the most relevant information,” the authors conclude.

    The researchers point out that this vision test could remove some of the limitations associated with standard IQ tests, which have been criticized for cultural bias. “Because the test is simple and non-verbal, it will also help researchers better understand neural processing in individuals with intellectual and developmental disabilities,” says co-author Loisa Bennetto, an associate professor of psychology at the University of Rochester.


  3. Study suggests genetic schizophrenia risk linked to lower IQ among people who do not develop schizophrenia

    May 23, 2013 by Ashley

    From the Elsevier press release via EurekAlert!:

    mental healthThe relationship between the heritable risk for schizophrenia and low intelligence (IQ) has not been clear. Schizophrenia is commonly associated with cognitive impairments that may cause functional disability.

    There are clues that reduced IQ may be linked to the risk for developing schizophrenia. For example, reduced cognitive ability may precede the onset of schizophrenia symptoms. Also, these deficits may be present in healthy relatives of people diagnosed with schizophrenia.

    In a remarkable new study published in Biological Psychiatry, Dr. Andrew McIntosh and his colleagues at the University of Edinburgh provide new evidence that the genetic risk for schizophrenia is associated with lower IQ among people who do not develop this disorder.

    The authors analyzed data from 937 individuals in Scotland who first completed IQ testing in 1947, at age 11. Around age 70, they were retested and their DNA was analyzed to estimate their genetic risk for schizophrenia.

    The researchers found that individuals with a higher genetic risk for schizophrenia had a lower IQ at age 70 but not at age 11. Having more schizophrenia risk-related gene variants was also associated with a greater decline in lifelong cognitive ability.

    If nature has loaded a person’s genes towards schizophrenia, then there is a slight but detectable worsening in cognitive function between childhood and old age. With further research into how these genes affect the brain, it could become possible to understand how genes linked to schizophrenia affect people’s cognitive function,” said McIntosh.

    These findings suggest that common genetic variants may underlie both cognitive aging and risk of schizophrenia.

    “While this study does not show that these common gene variants produce schizophrenia per se, it elegantly suggests that these variants may contribute to declines in intelligence, a clinical feature associated with schizophrenia,” commented Dr. John Krystal, Editor of Biological Psychiatry. “However, we have yet to understand the development of cognitive impairments that produce disability in young adulthood, the period when schizophrenia develops for many affected people.”

    Clearly, more research is necessary, but this new study adds to the growing and substantial effort to understand how the gene variants that contribute to the development of schizophrenia give rise to the cognitive disability commonly associated with it.

     


  4. Study links flame retardants to hyperactivity, lower intelligence

    May 6, 2013 by Ashley

    From the University of Cincinnati press release via HealthCanal:

    lab_researchA new study led by researchers at the University of Cincinnati (UC) College of Medicine shows that prenatal exposure to chemical flame retardants used in everyday products such as baby strollers, carpeting and electronics is associated with hyperactivity and lower intelligence in early childhood.

    The research on the chemicals, known as polybrominated diphenyl ethers (PBDEs), is being presented Monday, May 6, at the Pediatric Academic Societies (PAS) annual meeting in Washington, D.C. The study’s lead author is Aimin Chen, MD, PhD, an assistant professor of environmental health at UC.

    “In animal studies, PBDEs can disrupt thyroid hormone and cause hyperactivity and learning problems,” says Chen. “Our study adds to several other human studies to highlight the need to reduce exposure to PBDEs in pregnant women.”

    Chen and his colleagues at UC collected blood samples from 309 pregnant women enrolled in a study at Cincinnati Children’s Hospital Medical Center to measure PBDE levels. They also performed intelligence and behavior tests on the women’s children annually until they were 5 years old.

    We found that maternal exposure to PBDEs, a group of brominated flame retardants mostly withdrawn from the U.S. market in 2004, was associated with deficits in child cognition at age 5 years and hyperactivity at ages 2 to 5 years,” Chen says. A 10-fold increase in maternal PBDEs was associated with about a four-point IQ deficit in 5-year-old children.

    Even though PBDEs, except Deca-BDEs, are not used as a flame retardant in the United States anymore, they are found on many consumer products bought several years ago. In addition, the chemicals are not easily biodegradable, so they remain in human tissues and are transferred to the developing fetus.

    Because PBDEs exist in the home and office environment as they are contained in old furniture, carpet pads, foams and electronics, the study raises further concern about their toxicity in developing children,” Chen says.

     


  5. Study suggests emotional intelligence trumps IQ in dentist-patient relationships

    April 29, 2013 by Ashley

    From the Case Western Reserve University press release via ScienceDaily:

    TeethIQ directly relates to how students perform on tests in the first two years of dental school. But emotional intelligence (EI) trumps IQ in how well dental students work with patients, report researchers from Case Western Reserve University’s School of Dental Medicine and Weatherhead School of Management.

    EI influences how well dental students recognize and manage their emotions and professional relationships, explain Kristin Victoroff, DDS, PhD, and Richard Boyatzis, PhD, in the current issue of the Journal of Dental Education article, “What is the Relationship Between Emotional Intelligence and Dental School Clinical Performance?”

    EI differs from IQ, which measures the ability to think and perform on tests. EI, also a form of intelligence, is the ability to read one’s own moods and those of others, remain calm under pressure and be optimistic and adaptable to change.

    “Emotional intelligence is distinct from traditional intelligence or IQ,” said Boyatzis, a Distinguished University Professor and professor of organizational behavior, psychology and cognitive science. He developed the EI management model and coauthored a book series on how to use it in business. He added that people need both to be successful.

    The study evolved from discussions by heath-care educators about whether EI should be used in the admissions process or as a measure in clinical practice.

    Boyatzis explained that other standardized admissions tests are equally incapable of predicting success in other fields, like medicine and management. “Such tests predict grades in courses but not effectiveness in professions. This is the first test of this relationship in dentistry, and one of the clearest studies of the dynamics,” he said.

    Until now, no evidence was available to determine if EI had a connection to clinical education, said Victoroff, the associate dean for education and associate professor of community dentistry.

    The highly competitive admission process to dental school involves high scores on academic and perceptual ability tests. But that could change as educators understand the important role of EI in patient care.

    Educators questioned why some high-performing students in the classroom didn’t fare as well in the clinic. Researchers wondered if EI was a factor.

    Students at Case Western Reserve dental school were among the first in dentistry to see if EI impacted clinical successes, as it does in corporate management.

    The researchers recruited third- and fourth-year students, who receive clinical training under the guidance of two preceptors (part-time faculty who are practicing community dentists) that assess clinical performance.

    One hundred of the 136 students from the two classes participated. Students themselves plus other individuals they work with were asked to complete a 72-item questionnaire from the Emotional Competence Inventory-University. EI competencies are grouped in four areas: self-awareness, self-management, social-awareness and relationship management.

    Overall clinical performance was determined by averaging the preceptors’ assessments of a student’s overall clinical performance over several rating periods.

    In determining a student’s overall clinical performance, preceptors consider such factors as diagnosis and treatment planning skills, work ethic and time utilization, preparation and organization, professionalism, patient management, knowledge and technical skills and ability to self-assess one’s work.

    The analysis looked at the clinical grade and the EI assessment to see if there was a correlation between high EI scores and high clinical performance. The researchers ruled out the student’s year in school and gender in the analysis after finding those factors made no significant differences.

    Their findings showed that a high EI related to excellent clinical performance. The researchers found EI skills in self-management were significant predictors of clinical grades. Self-management skills involve self-control, achievement orientation, initiative, trustworthiness, conscientiousness, adaptability and optimism.

    They did not find a strong EI-clinical association to self- and social-awareness.

    EI scores for relationship management, which relates to the ability to influence others, were harder to determine due to the transient nature between the student dentist and patient during the two-year clinical training.

    The researchers concluded that teaching EI competencies could better serve patients and help students succeed. They recommended future studies extend EI assessments to practicing dentists to determine EI’s impact in the professional setting.


  6. Study suggests having breakfast daily may help children’s IQ scores

    February 19, 2013 by Ashley

    From the University of Pennsylvania School of Nursing press release via ScienceDaily:

    breakfast timeNew research from the University of Pennsylvania School of Nursing has found that children who regularly have breakfast on a near-daily basis had significantly higher full scale, verbal, and performance IQ test scores.

    In one of the first studies to examine IQ and breakfast consumption, researchers examined data from 1,269 children six years old in China, where breakfast is highly valued, and concluded that children who did not eat breakfast regularly had 5.58 points lower verbal, 2.50 points lower performance, and 4.6 points lower total IQ scores than children who often or always ate breakfast after adjusting for seven sociodemographic confounders.

    Childhood is a critical period in which dietary and lifestyle patterns are initiated, and these habits can have important immediate and long-term implications,” said lead author Jianghong-Liu, PhD, RN, FAAN, associate professor at Penn Nursing. “Breakfast habits appear to be no exception, and irregular breakfast eating has already been associated with a number of unhealthy behaviors, such as smoking, frequent alcohol use, and infrequent exercise.”

    At age 6, a child’s cognitive ability as both the verbal and performance levels is rapidly developing. Both the nutritional and social aspects of breakfast play a role. After a whole night of fasting, breakfast serves as a means to supply “fuel” to the brain. Meanwhile, social interaction at breakfast time with parents may promote brain development. Mealtime discussions may facilitate cognitive development by offering children the opportunity to expand their vocabulary, practice synthesizing and comprehending stories, and acquire general knowledge, noted the authors.

    The researchers suggest that schools play a role in stressing the importance of eating breakfast by delaying start times and/or providing breakfast to allow students to profit from the cognitive benefits of eating before a morning curriculum.

    “Because adequate nutrition in early childhood has been linked to increased IQ through childhood, which is related to decreased childhood behavioral disorders, better career satisfaction, and socioeconomic success in adults, breakfast consumption could ultimately benefit long-term physical and mental health outcomes as well a quality of life,” said Dr. Liu. “These findings may reflect nutritional as well as social benefits of breakfast consumption on children and hold important public health implications regarding regular breakfast consumption in early young children.

    This study was based on data collected from the China Jintan Child Cohort Study, led by Dr. Liu, an on-going prospective longitudinal study with the main aim of assessing the early health risk factors for the development of child neurobehavioral outcomes. The study was funded by the National Institute of Environmental Health Sciences.


  7. Study suggests nutrition, parental behaviour and preschool can boost children’s IQ

    February 1, 2013 by Ashley

    From the Association for Psychological Science press release:

    sleeping childSupplementing children’s diets with fish oil, enrolling them in quality preschool, and engaging them in interactive reading all turn out to be effective ways to raise a young child’s intelligence, according to a new report published in Perspectives on Psychological Science, a journal of the Association for Psychological Science.

    Using a technique called meta-analysis, a team led by John Protzko, a doctoral student at the NYU Steinhardt School of Culture, Education, and Human Development, combined the findings from existing studies to evaluate the overall effectiveness of each type of intervention. In collaboration with NYU Steinhardt professors Joshua Aronson and Clancy Blair, leaders in the field of intelligence, Protzko analyzed the best available studies involving samples of children from birth and kindergarten from their newly assembled “Database of Raising Intelligence.”

    “Our aim in creating this database is to learn what works and what doesn’t work to raise people’s intelligence,” said Protzko. “For too long, findings have been disconnected and scattered throughout a wide variety of journals. The broad consensus about what works is founded on only two or three very high-profile studies.

    All of the studies in this database rely on a normal population (participants without clinical diagnoses of intellectual disabilities), focus on interventions that are sustained over time, use widely accepted measures of intelligence, and, most importantly, are randomly controlled trials (participants selected at random to receive one of the interventions).

    The larger goal here is to understand the nature of intelligence, and if and how it can be nurtured at every stage of development,” said Aronson, Protzko’s advisor. “This is just a first step in a long process of understanding. It is by no means the last word. In fact, one of the main conclusions is how little high quality research exists in the field and how much more needs to be done.”

    Overall, the results of the meta-analyses indicated that certain dietary and environmental interventions can be effective in raising children’s IQ.

    Supplementing pregnant women and newborns with long-chain polyunsaturated fatty acids, foods rich in Omega-3, were found to boost children’s IQ by more than 3.5 points. These essential fatty acids may help raise intelligence by providing the building blocks for nerve cell development that the body cannot produce on its own.

    There is insufficient research, however, to determine whether other types of supplements — including iron, B-complex vitamins, riboflavin, thiamine, niacin, and zinc — have beneficial effects on intelligence.

    Enrolling an economically disadvantaged child into an early education intervention was found to raise his or her IQ by more than four points; interventions that specifically included a center-based education component raised a child’s IQ by more than seven points.

    The researchers hypothesize that early education interventions may help to raise children’s IQ by increasing their exposure to complex environments that are cognitively stimulating and demanding. It’s not clear, however, whether these results apply more broadly to kids from different socioeconomic backgrounds.

    Surprisingly, Protzko, Aronson, and Blair found no evidence to support the idea that early education interventions that take place earlier in childhood are more effective than those that begin later.

    Interventions focused on interactive reading — teaching parents how to engage their children while reading with them — were found to raise children’s IQ by over 6 points. These interventions do not seem to have an effect for children over 4 years old, suggesting that the interventions may accelerate language development, which, in turn, boosts IQ.

    Sending a child to preschool was found to raise his or her IQ by more than four points, and preschools that include a language development component were found to boost IQ by more than seven points. The link between preschool and intelligence could be a function of increased exposure to language or the result of the overall cognitive complexity of the preschool environment.

    “Our current findings strengthen earlier conclusions that complex environments build intelligence, but do cast doubt on others, including evidence that earlier interventions are always most effective,” Protzko explained. “Overall, identifying the link between essential fatty acids and intelligence gives rise to tantalizing new questions for future research and we look forward to exploring this finding.”

     


  8. Study suggests measuring IQ by singular standardized test may be misleading

    December 30, 2012 by Sue

    From the University of Western Ontario press release via EurekAlert!:

    studying_hardAfter conducting the largest online intelligence study on record, a Western University-led research team has concluded that the notion of measuring one’s intelligence quotient or IQ by a singular, standardized test is highly misleading.

    The findings from the landmark study, which included more than 100,000 participants, were published today in the journal Neuron. The article, “Fractionating human intelligence,” was written by Adrian M. Owen and Adam Hampshire from Western’s Brain and Mind Institute (London, Canada) and Roger Highfield, Director of External Affairs, Science Museum Group (London, U.K).

    Utilizing an online study open to anyone, anywhere in the world, the researchers asked respondents to complete 12 cognitive tests tapping memory, reasoning, attention and planning abilities, as well as a survey about their background and lifestyle habits.

    “The uptake was astonishing,” says Owen, the Canada Excellence Research Chair in Cognitive Neuroscience and Imaging and senior investigator on the project. “We expected a few hundred responses, but thousands and thousands of people took part, including people of all ages, cultures and creeds from every corner of the world.”

    The results showed that when a wide range of cognitive abilities are explored, the observed variations in performance can only be explained with at least three distinct components: short-term memory, reasoning and a verbal component.

    No one component, or IQ, explained everything. Furthermore, the scientists used a brain scanning technique known as functional magnetic resonance imaging (fMRI), to show that these differences in cognitive ability map onto distinct circuits in the brain.

    With so many respondents, the results also provided a wealth of new information about how factors such as age, gender and the tendency to play computer games influence our brain function.

    “Regular brain training didn’t help people’s cognitive performance at all yet aging had a profound negative effect on both memory and reasoning abilities,” says Owen.

    Hampshire adds, “Intriguingly, people who regularly played computer games did perform significantly better in terms of both reasoning and short-term memory. And smokers performed poorly on the short-term memory and the verbal factors, while people who frequently suffer from anxiety performed badly on the short-term memory factor in particular”.

    To continue the groundbreaking research, the team has launched a new version of the tests at http://www.cambridgebrainsciences.com/theIQchallenge

    “To ensure the results aren’t biased, we can’t say much about the agenda other than that there are many more fascinating questions about variations in cognitive ability that we want to answer,” explains Hampshire.


  9. Study suggests even moderate drinking in pregnancy can affect a child’s IQ

    November 19, 2012 by Sue

    From the University of Bristol press release via EurekAlert!:

    alcohol and pregnancyRelatively small levels of exposure to alcohol while in the womb can influence a child’s IQ, according to a new study led by researchers from the universities of Bristol and Oxford using data from over 4,000 mothers and their children in the Children of the 90s study (ALSPAC) and published today in PLOS ONE.

    Current advice to pregnant women about moderate alcohol consumption during pregnancy is contradictory, with some official guidelines recommending complete abstinence and others suggesting that moderate use is safe.

    Previous studies have produced conflicting and inconsistent evidence on the effects of moderate alcohol intake on a child’s IQ. This may be because it is difficult to separate the effects of moderate alcohol consumption from other lifestyle and social factors, such as smoking, diet, affluence, mother’s age and education.

    This study, believed to be the first substantial one of its kind, used genetic variation to investigate the effects of moderate (<1-6 units of alcohol per week) drinking during pregnancy among a large group of women and their children. Since the individual variations that people have in their DNA are not connected to lifestyle and social factors, the approach removes that potential complication.

    Four genetic variants in alcohol-metabolising genes among the 4,167 children were strongly related to lower IQ at age eight. The child’s IQ was on average almost two points lower per genetic modification they possessed.

    But this effect was only seen among the children of women who were moderate drinkers. There was no effect evident among children whose mothers abstained during pregnancy, strongly suggesting that it was the exposure to alcohol in the womb that was leading to the difference in child IQ. Heavy drinkers were not included in the study.

    When a person drinks alcohol, ethanol is converted to acetaldehyde by a group of enzymes. Variations in the genes that ‘encode’ these enzymes lead to differences in their ability to metabolise ethanol. In ‘slow metabolisers’, peak alcohol levels may be higher and persist for longer than in ‘fast metabolisers’.

    It is believed that the ‘fast’ metabolism of ethanol protects against abnormal brain development in infants because less alcohol is delivered to the fetus, although the exact mechanisms are still unclear.

    Previous studies have relied on observational evidence, but this is problematic. Observational studies often find that moderate drinking is beneficial compared to abstention, but this is because mothers who drink in moderation during pregnancy are typically well educated, have a good diet and are unlikely to smoke – all factors which are linked to higher IQ in the child, and which mask any negative effect that exposure to alcohol may have.

    This study, on the other hand, looked at moderate (rather than high) alcohol intake in over 4,000 women and used a novel technique known as Mendelian randomization, which is a scientifically robust way of investigating the links between exposures and later diseases, using genetic variants which modify exposure levels and which are not influenced by lifestyle or other factors.

    The mothers’ alcohol intake was based on a questionnaire completed when they were 18 weeks’ pregnant. It included questions on the average amount and frequency of alcohol consumption before the current pregnancy, during the first trimester, and in the previous two weeks or at the time when they first felt the baby move. One drink was specified as one unit of alcohol.

    Around 32 weeks of gestation the mother completed another questionnaire in which she was asked about her average weekday and weekend alcohol consumption, from which weekly intake was derived. Any woman who reported drinking, even if it was less than one unit per week either in the first trimester or when she felt the baby first move was classified as drinking during pregnancy.

    At approximately 18 and 32 weeks of pregnancy, the women were also asked on how many days during the past month they had drunk two pints of beer (or the equivalent amount of alcohol). Any women who reported doing this on at least one occasion was classified as a binge drinker for the purposes of this analysis and were excluded.

    The children’s IQ was tested when they were aged eight using a shortened version of the Wechsler Intelligence Scale for Children from which an overall age adjusted total score was derived.

    Speaking about the findings, the report’s main author, Dr Sarah Lewis, said:

    ‘Our results suggest that even at levels of alcohol consumption which are normally considered to be harmless, we can detect differences in childhood IQ, which are dependent on the ability of the foetus to clear this alcohol. This is evidence that even at these moderate levels, alcohol is influencing foetal brain development.’

    Dr Ron Gray from the University of Oxford who led the research added:

    ‘This is a complex study but the message is simple: even moderate amounts of alcohol during pregnancy can have an effect on future child intelligence. So women have good reason to choose to avoid alcohol when pregnant.’


  10. Study links exercise to higher IQ in women

    November 1, 2012 by Sue

    From the McLean Hospital press release via HealthCanal:

    Exercise BikePrevious research has shown that cognitive performance is associated with regular exercise among children and elderly, and now researchers at Harvard Medical School’s McLean Hospital have shown a similar correlation for non-geriatric adult women.

    As reported in the current issue of the journal Perceptual & Motor Skills, William D. S. Killgore, PhD, and Zachary J. Schwab, BS, asked healthy adult men and women from the Boston area to gauge their weekly exercise habits and then take an intelligence test. Higher intelligence matched with exercise frequency and duration for women — but not for men.

    Intelligence, the authors said, was linked to workout frequency and the total minutes of exercise per week, and the findings remained even when considering demographic variables that normally affect physical activity and intelligence. What is not known, however, is whether more exercise actually causes higher IQ or whether higher IQ leads women to exercise more.

    “Overall, these findings suggest that physical exercise is significantly related to relatively stable intellectual capacities among healthy adults,” the authors wrote. “The relationship between physical exercise and measured intelligence was most evident for women.”

    Perceptual & Motor Skills, established in 1949, is an independent, peer-reviewed, bimonthly journal which specializes in empirical, theoretical, mainstream, and alternative views on issues in perception and motor skills.