Western university-led research debunks IQ myth

After 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, standardised test is highly misleading.

The findings from the landmark study, which included more than 100,000 participants, were published in the journal Neuron.

Utilising 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 ageing 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 ground-breaking research, the team has launched a new version of the tests “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.

sciencenewsline

Poor people eat more salt

People from low socio-economic positions eat more salt than the well off, irrespective of where they live, states a paper published in the BMJ Open journal.

The research was carried out by the World Health Organisation Collaborating Centre for Nutrition , based in the Division of Mental Health Well-being of Warwick Medical School at the University of Warwick. The study looked at the geographical distribution of habitual dietary salt intake and its association with manual occupations and educational attainments, both indicators of socio-economic position and key determinants of health.

The researchers used the British National Diet and Nutrition Survey (2000-1), a national representative sample of 2,105 men and women aged 19-64 years living in Britain.

Salt intake was assessed with two independent methods: a seven-day dietary record and the ‘gold standard’ 24h urine collections for sodium determination (direct marker of salt intake).

The study provides evidence for the first time that salt intake is significantly higher in those with low educational attainment and in manual occupations, when the effects of geographical variations are stripped out (people living in Scotland had higher salt intake than those in England and Wales).

Prof Francesco Cappuccio, said: “These results are important as they explain in part why people of low socio-economic background are more likely to develop high blood pressure and to suffer disproportionately from strokes heart attacks and renal failure.”

Teresa Morris of The Bupa Foundation, said: “Habitual salt intake in most adult populations around the world exceeds 10g per day and the World Health Organisation recommends that daily intake should not exceed 5 g .

“Population salt reduction programs are a cost-effective way of reducing the burden of cardiovascular disease nationally and globally.”

Professor Cappuccio said: “We have seen a reduction in salt intake in Britain from 9.5 to 8.1 g per day in the period 2004-2011, thanks to an effective policy which included awareness campaigns, food reformulation and monitoring.

“Whilst this is an achievement to celebrate, our results suggest the presence of social inequalities in levels of salt intake that would underestimate the health risks in people who are worse off - and these are the people who need prevention most.

“The diet of disadvantaged socio-economic groups tends to be made up of low-quality, salt-dense, high-fat, high-calorie unhealthy cheap foods. “Behavioural approaches to healthy eating are unlikely to bring about the changes necessary to halt the cardiovascular epidemic and would also widen inequalities. “Since the majority of dietary salt is added during commercial food production, widespread and continued food reformulation is necessary through both voluntary as well as regulatory means to make sure that salt reduction is achieved across all socio economic groups”, Professor Cappuccio concluded.

- MNT

Pronunciation of‘s’ sounds reveals gender

A person's style of speech - not just the pitch of his or her voice - may help determine whether the listener perceives the speaker to be male or female, according to a researcher who studied transgender people transitioning from female to male. The way people pronounce their “s” sounds and the amount of resonance they use when speaking contributes to the perception of gender, according to Lal Zimman, whose findings are based on research he completed while earning his doctoral degree from CU-Boulder's linguistics department.

Zimman, who graduated in August, presented his research at the annual meeting of the Linguistic Society of America in Boston.

“In the past, gender differences in the voice have been understood, primarily, as a biological difference,” Zimman said.

“I really wanted to look at the potential for other factors, other than how testosterone lowers the voice, to affect how a person's voice is perceived.” As part of the process of transitioning from female to male, participants in Zimman's study were treated with the hormone testosterone, which causes a number of physical changes including the lowering of a person's voice. Zimman was interested in whether the style of a person's speech had any impact on how low a voice needed to drop before it was perceived as male.

What he found was that a voice could have a higher pitch and still be perceived as male if the speaker pronounced “s” sounds in a lower frequency, which is achieved by moving the tongue farther away from the teeth.

“A high-frequency ‘s’ has long been stereotypically associated with women's speech, as well as gay men's speech, yet there is no biological correlate to this association,” said CU-Boulder linguistics and anthropology Associate Professor Kira Hall, who served as Zimman's doctoral adviser.

“The project illustrates the socio-biological complexity of pitch: the designation of a voice as more masculine or more feminine is importantly influenced by other ideologically charged speech traits that are socially, not biologically, driven.”

Vocal resonance also affected the perception of gender in Zimman's study.

A deeper resonance - which can be thought of as a voice that seems to be emanating from the chest instead of from the head - is the result of both biology and practice.

Resonance is lower for people whose larynx is deeper in their throats, but people learn to manipulate the position of their larynx when they're young, with male children pulling their larynxes down a little bit and female children pushing them up, Zimman said.

For his study, Zimman recorded the voices of 15 transgender men, all of whom live in the San Francisco Bay area. To determine the frequency of the “s” sounds each participant made, Zimman used software developed by fellow linguists.

Then, to see how the “s” sounds affected perception, Zimman digitally manipulated the recording of each participant's voice, sliding the pitch from higher to lower, and asked a group of 10 listeners to identify the gender of the speaker.

Using the recordings, Zimman was able to pinpoint how low each individual's voice had to drop before the majority of the group perceived the speaker to be male.

- MNT

Epilepsy and migraine may be genetically linked

New research reveals a shared genetic susceptibility to epilepsy and migraine. Findings published in Epilepsia, a journal of the International League Against Epilepsy (ILAE), indicate that having a strong family history of seizure disorders increases the chance of having migraine with aura (MA).

Medical evidence has established that migraine and epilepsy often co-occur in patients; this co-occurrence is called “co-morbidity.” Previous studies have found that people with epilepsy are substantially more likely than the general population to have migraine headache. However, it is not clear whether that co-morbidity results from a shared genetic cause.

“Epilepsy and migraine are each individually influenced by genetic factors,” explains lead author Dr. Melodie Winawer from Columbia University Medical Center in New York. “Our study is the first to confirm a shared genetic susceptibility to epilepsy and migraine in a large population of patients with common forms of epilepsy.”

For the present study, Dr. Winawer and colleagues analysed data collected from participants in the Epilepsy Phenome/Genome Project(EPGP) - a genetic study of epilepsy patients and families from 27 clinical centres in the U.S., Canada, Argentina, Australia, and New Zealand. The study examined one aspect of EPGP: sibling and parent-child pairs with focal epilepsy or generalized epilepsy of unknown cause. Most people with epilepsy have no family members affected with epilepsy. EPGP was designed to look at those rare families with more than one individual with epilepsy, in order to increase the chance of finding genetic causes of epilepsy.

Analysis of 730 participants with epilepsy from 501 families demonstrated that the prevalence of MA - when additional symptoms, such as blind spots or flashing lights, occur prior to the headache pain - was substantially increased when there were several individuals in the family with seizure disorders.

EPGP study participants with epilepsy who had three or more additional close relatives with a seizure disorder were more than twice as likely to experience MA than patients from families with fewer individuals with seizures. In other words, the stronger the genetic effect on epilepsy in the family, the higher the rates of MA.

This result provides evidence that a gene or genes exist that cause both epilepsy and migraine.

Identification of genetic contributions to the co-morbidity of epilepsy with other disorders, like migraine, has implications for epilepsy patients.

Prior research has shown that coexisting conditions impact the quality of life, treatment success, and mortality of epilepsy patients, with some experts suggesting that these co-morbidities may have a greater impact on patients than the seizures themselves.

In fact, co-morbid conditions are emphasised in the National Institutes of Health Epilepsy Research Benchmarks and in a recent report on epilepsy from the Institute of Medicine.

“Our study demonstrates a strong genetic basis for migraine and epilepsy, because the rate of migraine is increased only in people who have close (rather than distant) relatives with epilepsy and only when three or more family members are affected,” concludes Dr. Winawer.

“Further investigation of the genetics of groups of co-morbid disorders and epilepsy will help to improve the diagnosis and treatment of these co-morbidities, and enhance the quality of life for those with epilepsy.

- sciencedaily

Brain development may be hindered by modern parenting

Social practices and cultural beliefs of modern life are preventing healthy brain and emotional development in children, according to an interdisciplinary body of research presented recently at a symposium at the University of Notre Dame.

“Life outcomes for American youth are worsening, especially in comparison to 50 years ago,” says Darcia Narvaez, Notre Dame professor of psychology. “Ill-advised practices and beliefs have become commonplace in our culture, such as the use of infant formula, the isolation of infants in their own rooms or the belief that responding too quickly to a fussing baby will ‘spoil’ it,” Narvaez says. This new research links certain early, nurturing parenting practices - the kind common in foraging hunter-gatherer societies - to specific, healthy emotional outcomes in adulthood, and has many experts rethinking some of our modern, cultural childrearing “norms.”

“Breast-feeding infants, responsiveness to crying, almost constant touch and having multiple adult caregivers are some of the nurturing ancestral parenting practices that are shown to positively impact the developing brain, which not only shapes personality, but also helps physical health and moral development,” says Narvaez.

Studies show that responding to a baby's needs (not letting a baby “cry it out”) has been shown to influence the development of conscience; positive touch affects stress, impulse control and empathy; free play in nature influences social capacities and aggression, and a set of supportive caregivers (beyond mother alone) predicts IQ and ego resilience as well as empathy.

The United States has been on a downward trajectory on all of these care characteristics, according to Narvaez. Instead of being held, infants spend much more time in carriers, car seats and strollers than they did in the past. Only about 15 percent of mothers are breastfeeding at all by 12 months, extended families are broken up and free play allowed by parents has decreased dramatically since 1970.

Whether the corollary to these modern practices or the result of other forces, research shows an epidemic of anxiety depression among all age groups, including young children; rising rates of aggressive behaviour and delinquency in young children; and decreasing empathy, the backbone of compassionate, moral behaviour, among college students.

According to Narvaez, however, other relatives and teachers also can have a beneficial impact when a child feels safe in their presence. Also, early deficits can be made up later, she says. “The right brain, which governs much of our self-regulation, creativity and empathy, can grow throughout life.

The right brain grows though full-body experience like rough-and-tumble play, dancing or freelance artistic creation. So at any point, a parent can take up a creative activity with a child and they can grow together.

- MNT