Background noise may hinder toddlers’ ability to learn words
Also in health news: oxygen deprivation may be key to human birth defects; and moderate exercise may be better for the pre-diabetic than very vigorous workouts
The environments children are in, including how much and the kind of stimulation they are exposed to, influence what and how they learn. Children need to zero in on information that’s relevant and ignore what isn’t. A new study has found that background noise makes it more difficult for toddlers to learn new words. The study also found that providing additional language cues may help young children overcome the effects of noisy environments. Conducted at the University of Wisconsin-Madison, the research appears in the journal Child Development.
“Learning words is an important skill that provides a foundation for children academically,” says Brianna McMillan, a student in psychology who led the study. “Modern homes are filled with noisy distractions that could affect how children learn words. Adults should be aware of background noise in the environment when they interact.”
In the study, 106 children aged 22 to 30 months took part in three experiments in which they were taught names for unfamiliar objects and tested on their ability to recognise the objects when they were labelled. The environments ranged from quiet to loud.
While louder background speech hindered toddlers’ ability to learn words, cues in the environment helped them overcome this difficulty. “Hearing new words in fluent speech without a lot of background noise before trying to learn what objects the new words correspond to may help very young children master new vocabulary,” suggests Jenny Saffran, professor of psychology at the university, who co-authored the study. “In a noisy environment, drawing their attention to the sounds of the new word may help them compensate.”
World-first discovery gets to the heart of birth defects
For the first time, scientists believe they’ve discovered a cause of many types of birth defects triggered by environmental stresses, including pollution. The breakthrough, made by scientists at the Victor Chang Institute in Australia, shows that cellular stress could be key to understanding why babies are born with defects of the heart, vertebrae and kidneys, among others.
The researchers analysed the effects of short-term oxygen deficiency on heart development in mouse embryos. In a lab, oxygen levels inside a chamber were reduced from the normal level of 21 per cent to as low as 5.5 per cent for eight hours.
“We discovered that reduced oxygen triggered a stress response in the embryonic cells. The cells try to relieve the stress by stopping protein production. Suddenly those proteins aren’t available to make the heart at a critical time and the heart doesn’t develop properly,” says Professor Sally Dunwoodie, lead researcher.
Oxygen deficiency in an embryo can be caused by many things, she says such as smoking, prescription medication, high blood pressure, high altitude, a tangled umbilical cord and carbon monoxide.
Other factors can also trigger this cellular stress, such as viral infections, increased temperature, high blood glucose, poor nutrition and pollution.
“This cellular stress response could be the key to a variety of birth defects, not just heart defects. Now, we strongly suspect it’s an underlying mechanism for many different types of birth defects, including those of the vertebrae, kidneys and others,” says Dunwoodie.
The study has recently been accepted for publication in the journal Development.
Moderate exercise may work better at combating pre-diabetes
Walking briskly on a regular basis may be more effective than vigorous jogging for improving glucose control in individuals with pre-diabetes, according to research from Duke University Medical Centre in North Carolina.
The six-month study involved 150 pre-diabetic participants who were randomly assigned to one of four groups. The first group followed an intervention modelled after the Diabetes Prevention Programme (DPP), considered a gold standard, that aims to achieve a 7 per cent body weight reduction over six months through a low-fat calorie-restricted diet and moderate-intensity exercise equivalent to 12km of brisk walking a week. The other three groups did exercise only at different amounts and intensities: a low amount at moderate intensity (equivalent to walking briskly for 12km per week); a high amount at moderate intensity (equivalent to walking briskly for 18.5km per week); and a high amount at vigorous intensity (equivalent to jogging 8.5km per week).
“We know the benefits of lifestyle changes from the DPP, but it is difficult to get patients to follow even one behaviour, let alone three,” says lead author Dr William Kraus.
On average, participants in the DPP group had the greatest benefit, with a 9 per cent improvement in oral glucose tolerance – a key measure of how readily the body processes sugar and an indicator used to predict progression to diabetes. Participants in the moderate intensity, 18.5km group came in a close second: they saw a 7 per cent improvement in glucose tolerance on average. The moderate intensity, 12km group had a 5 per cent improvement on average. The lowest improvement was seen among those in the vigorous intensity, 18.5km group, with only a 2 per cent average improvement.
“High intensity exercise tends to burn glucose more than fat, while moderate intensity exercise tends to burn fat more than glucose,” Kraus says. “We believe that one benefit of moderate intensity exercise is that it burns off fat in the muscles, which relieves the block of glucose uptake by the muscles. That’s important because muscle is the major place to store glucose after a meal.”