There is perhaps no parenting decision that tugs on the heartstrings as strongly as whether to let a baby cry him or herself to sleep.

At one end of the spectrum are parents who use some form of "cry-it-out" method to teach their baby to sleep through the night. The method is characterized by periods of letting a baby cry - from a few minutes to more than an hour - without picking him or her up. At the other end are the "no-cry" types who consider letting a baby cry for any length of time to be cruel and unusual punishment.

Stuck in the middle are a lot of exhausted parents hoping to make the right choice – especially since sleep deprivation in infants has been linked to behavioural and cognitive problems, not to mention its effects on mom and dad.

New research on infant sleep appears to deal a blow to those in the cry-it-out camp. Penn State researcher Douglas Teti examined the role of emotional availability on infant sleep and found that regardless of a family’s night-time routine, infants with parents who were responsive and warm had fewer night wakings and an easier time drifting off. In his study, which involved infrared cameras placed in families’ bedrooms and nurseries, a lapse of more than a minute resulted in a lower emotional availability score.

While more research is under way to further test those findings, Dr. Teti, a professor of human development and psychology, says his work adds to a growing skepticism toward sleep training – not only that it may not work, but that it may, in turn, affect the parent-child relationship itself.

Since his landmark book Solve Your Child’s Sleep Problems was published in 1985, pediatric sleep expert Richard Ferber has became the best known advocate of a “controlled-crying” approach. He advised parents to leave their infants in their cribs for increasingly longer periods of time, starting with a few minutes (the method spawned the verb “to Ferberize”). They were instructed to pat and comfort their baby through the crying, but not pick up or feed the baby.

Other authors and consultants have since added and subtracted behaviors to create their own formulas – staying in the room or not, being visible or not, soothing by voice or not, touching or not – though many caution against sleep training under six months. Parents often pick and choose from the methods, and some, misinterpreting Dr. Ferber’s technique, simply shut the door.

In Dr. Ferber’s second edition, published in 2006, he added a preface clarifying the difference between his method and a shut-the-door approach. “Simply leaving a child in a crib to cry for long periods alone until he falls sleep, no matter how long it takes, is not an approach I approve of,” he wrote.

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PregnancyWeekly.com

First-time moms who are older than 30, overweight or have breastfeeding difficulties on their newborn's first day may have increased odds of a delay in their full breast milk production, a new study suggests.

After giving birth, women produce a precursor to breast milk called colostrum until their full breast milk comes in; if that shift does not happen within 72 hours, researchers consider it "delayed lactogenesis."

The concern with this is that some infants may start to become dehydrated and lose excess weight (some weight loss after birth is normal), and that some mothers, worried and frustrated, may give up on breastfeeding.

However, new moms with a delay in full milk production should not be discouraged, said Dr. Laurie A. Nommsen-Rivers of Cincinnati Children's Hospital Medical Center in Ohio, the lead researcher on the new study.

Instead, she said, they should call their pediatrician or "lactation consultant" -- a specialist in breastfeeding issues who works in some hospitals and also in private practice.

With some support, Nommsen-Rivers said, mothers with delayed breast-milk production will "do just fine." She noted that nearly all new moms -- 98 percent -- have their milk come in within a week.

For the current study, published in the American Journal of Clinical Nutrition, Nommsen-Rivers and her colleagues looked at the factors associated with delayed lactation among 431 first-time mothers who gave birth at one California medical center.

The researchers focused on first-time mothers because they are significantly more likely than women who've given birth before to have a delay in their breast milk coming in.

Overall, the study found, 44 percent of the women took longer than 72 hours to have their milk come in -- which was assessed by asking the study participants whether their breasts felt "noticeably fuller" three days after giving birth.

Women who were overweight or obese were more likely than thinner women to have a delay; 45 percent and 54 percent, respectively, compared with 31 percent of normal-weight women. Age also appeared to be a factor, as 58 percent of women age 30 and older had a delay in their breast milk coming in, versus 39 percent of younger women.

In addition, mothers who said they had "breastfed well" at least twice during the first 24 hours of their newborn's life -- when colostrum is produced -- were less likely to have a delay in their milk coming in: 39 percent to 43 percent of these women had a delay, compared with 65 percent of mothers who reported only one or no instance of breastfeeding "well" in the first 24 hours.

Another factor related to delayed milk production was nipple soreness. Women who had more than mild soreness in the first few days after giving birth were less likely to have a delay than other women.

That soreness, the researchers note, may be an indicator of more-effective early breastfeeding, which would encourage full milk production.

It is not clear why relatively older age and heavier weight in the mother would be associated with a higher risk of delayed lactation, according to Nommsen-Rivers.

But both, she and her colleagues note, are related to greater odds of carbohydrate "intolerance" during pregnancy. Problems in sugar metabolism could be a factor in the higher risk of delays in full breast-milk production, they speculate.

Whatever the underlying mechanisms for the findings, Nommsen-Rivers said that the bottom line for women is to seek help for any early breastfeeding difficulties.

She suggested that during pregnancy, women try to see a provider who has an affiliation with a lactation consultant. A home visit from the consultant in the first couple days after a woman gives birth can help identify and address any breastfeeding difficulties.

Women who feel their milk has not come in within 72 hours should call their pediatrician, Nommsen-Rivers said. The doctor can weigh and assess the baby, and watch the mother breastfeed to help spot any problems.

To help support early breastfeeding success, the American Academy of Pediatrics recommends that women ask to have their newborn placed in skin-to-skin contact with them immediately after birth so that they can breastfeed.

Frequent feedings in the early days are also important, Nommsen-Rivers said. It is often recommended that women breastfeed every two hours, but she suggested that new moms try to breastfeed whenever their newborn "shows an interest," with cues such as "smacking" his or her lips.

The rate of delayed milk production in this study -- 44 percent -- is significant, according to Nommsen-Rivers. Past studies have shown that compared with U.S. women, those in less-developed nations, such as Peru and Guatemala, tend to have their milk come in more quickly.

Pinning down the reasons for that difference -- including the facets of modern maternity care that may be involved -- will be important, Nommsen-Rivers said.

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PregnancyWeekly.com

A new study in the Journal of Allergy and Clinical Immunology says that feeding infants formula in their first days of life prevents babies from developing an allergy to cow's milk.

In the study, the longest and largest prospective study of its kind, the researchers looked at the feeding history of 13,019 infants. Children who were started on infant formula containing cow's milk protein in the first through the 15th days of life were almost completely protected from developing Cows Milk Protein Allergy (CMA) -- 19 times more protected than babies fed cow's milk protein after 15 days. CMA can be dangerous to babies, leading to rashes, respiratory problems, shock and even death, so this boost to the immune system early in life acts as a "vaccination."

What's interesting about this study (besides the obvious) is they recommend that babies get one bottle of formula every day for the first 15 days of life. Something we've been told to avoid at all costs.

Introducing formula later than 15 days has no value and can even trigger a cow's milk allergy if given during the three- to five-month period after birth. Which is the previous recommendation for introducing a bottle, if not introducing formula.

The study doesn't advocate for formula or decry breastfeeding, explaining that you can nurse all day long, just slip in some formula at some point.

Of course, as the doctor points out, giving the baby a bottle is an excellent way for dad to step in and bond with the baby too.

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PregnancyWeekly.com

1. Avoid using most baby products.

   WebMD advises parents to keep their newborns away from harsh powders and shampoos to protect their delicate skin and immune systems.

2. There is a right and a wrong time for infant massage.

   Gagazine’s article on infant massage explains how the time just after a bath or diaper change is perfect for a little touch therapy. Try to avoid touch therapy when the baby appears hungry or cranky.

3. Be gentle when cleaning nipples.

   When breastfeeding an infant, Medline Plus recommends that mothers prevent drying and cracking nipples by avoiding soaps and drying with harsh cloths or motions. Uncomfortable nipples negatively affect both mother and child.

4. Cleanse baby acne with water.

   As a residual of connecting with his or her mother’s hormones, some newborns break out into small acne patches. Avoid using oils or lotions that can irritate it further, but very mild, all-natural soaps may work in more severe cases.

5. Wash cloth diapers with baking soda and rinse them with vinegar.

   Avoid using harsh detergents when cleaning cloth diapers, even those without artificial dyes or fragrances. A wash in baking soda and a rinse in vinegar should suffice.

6. Wash newborn eyes with water.

   Normal tear duct issues need to be discussed with a pediatrician, but parents needing to clean their newborn’s eyes can do so by simply wetting a soft cotton ball and gently scrubbing the gunk away.

7. Use steam to unblock nasal passages.

   While professional medical care may be needed in instances of severe illness, parents can alleviate some cold symptoms at home. Congestion, for example, can be cleared up using the steam from a hot shower.

8. Make newborns sleep on their backs.

   One preventative measure against sudden infant death syndrome (SIDS) involves having newborns sleep on their backs rather than their stomachs. They may feel less comfortable, but it helps bolster their chances of surviving the night.

9. Wash clothes thoroughly.

   Another WebMD tip, this time touting the importance of washing baby clothes in dye- and fragrance-free detergent before dressing infants.

10. Protect nipples with milk or lanolin.

    To prevent painful cracking, Medline Plus recommends leaving a little bit of milk on the nipple after feeding to keep the area moist. Alternately, cracking can also be avoided by applying 100% lanolin to the nipple. Never use any artificial chemicals near the area where an infant feeds.

11. Use natural cleaning products around the home.

    For added protection against contact with harsh chemicals that can make a newborn ill, take advantage of the disinfectant properties of natural substances such as vinegar, lemon juice, and baking soda.

12. Clean the umbilical cord with water and a Q-Tip.

    Be sure to use a Q-Tip wetted with clean - even sterile - water to keep the umbilical cord free of bacteria. Alcohol, honey, and goldenseal powder work as well.

13. Make homemade nasal drops.

    Combine saline and water together for nose drops suitable for safe cleaning of a newborn’s clogged nasal passages.

14. Extra water works as a laxative.

    As an alternative to glycerin laxatives, consider feeding a newborn a little extra water to unbind the constipation.

15. Bathe conservatively.

    WebMD recommends that newborns receive a gentle sponge bath 2 to 3 times a week, as washing them too much compromises the health of their skin. Use either no soap or extremely mild, natural soap to prevent any dermal irritations.

16. Avoid “baby bottle tooth decay.”

    Breast milk makes for one of the healthiest, most natural ways to keep a newborn healthy and strong, but blending it with foods and drinks pumped full of refined sugar actually expatiates the process of tooth decay.

17. Know how to properly store soiled cloth diapers.

    Become familiar with the wet pail and dry pail methods of containing the odor and bacteria associated with cloth diapers. Wet pails must be contentiously kept covered in order to prevent drowning.

18. Keep the crib nearby - even at night.

    The American SIDS Institute recommends parents allow their newborn’s crib to remain in their room for the first 6 months of life, as dong so greatly reduces the risk of suffering the condition.

19. A little sunlight can clear up jaundice.

    A little extra bilirubin is normal in newborn infants, and a bit of time in the sunlight - no more than 10 minutes, with 5 minutes each in the front and the back - can clear up any jaundice that may crop up. Of course, a physician should be consulted if it doesn’t clear.

20. Use warm compresses on ingrown nails.

    While ingrown nails may grow severe enough to warrant medical attention, mild cases may be relieved using very warm compresses that alleviate a newborn’s pain.

21. Stick with soft clothing.

    According to WebMD, dressing children in clothes cut from coarser materials heightens the risk of eczema, rashes, and other uncomfortable skin conditions. Organic cotton, bamboo, ore hemp are all extremely appropriate choices.

22. Formula feeding tricks the body.

    Medline Plus recommends that women whose breast milk supplies start to run low fight the temptation to supplement a baby’s diet with formula. Doing so, especially when the newborn begins to experience a growth spurt, only forces the body to think that it is producing enough milk and will cease to bolster the supply.

23. Make homemade cloth wipes.

    Making gentle wipes at home with a combination of water, tea tree oil, and Dr. Bronner’s organic, natural soap (or similar substitutesaves money and leaves baby’s skin feeling smooth and clean. However, avoid using oils and soaps on especially sensitive, acne-prone newborns.

24. Moisturize, if needed.

    Should a newborn’s skin begin to dry out and crack, parents may want to moisturize the irritated areas with olive or almond oil applied very gently using a cotton ball.

25. Know when to trim nails.

    In order to prevent a newborn from scratching and potentially causing self-injury, clip his or her fingernails once a week and toenails once a month. Try doing so after a bath when the keratin is more malleable, though some opt for when the infant naps to prevent fussiness and fidgeting.

26. Know how to trim nails.

    When clipping a newborn’s nails, be sure to use special trimmers or scissors to prevent any unfortunate injuries. Cut along the natural lines when it comes to fingernails, but go straight across when doing the toes. On both, make a contentious effort to push down the pads of skin away from the nail to further reduce the risk of an accidental cutting.

27. Never clean the inside of a newborn’s ear canal.

    Parents may clear wax away on the outside of a newborn’s ear using extremely gentle swabs with a Q-Tip. Sticking it inside the baby’s ear canal, however, runs the risk of causing permanent hearing loss. Pediatricians will be able to give more information on removing internal excess wax without exacting any damages.

28. Make homemade baby shampoo.

    For instances when water may just not be enough, parents may want to whip up a batch of this all-natural baby shampoo to scrub out the germs without causing skin issues.

29. Use natural insect repellent.

    Many companies sell products that repel mosquitoes and other pests without the use of harsh chemical blends that will irritate a newborn’s skin. Seek these out - they usually contain eucalyptus and lemon and often come formulated especially for people under 12 months.

30. Pat dry - don’t rub.

    When changing diapers, WebMD thinks that parents need to spritz their newborns with clean water and pat dry rather than rub to keep skin from becoming too irritated.

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PregnancyWeekly.com

Scientists have long known that breast milk is best for babies because it provides components that protect the immune system and help reduce an infant's risk for developing infections. What researchers did not know was how and why breast milk specifically protects infants, but now they are closer to an answer.

Scientists at the University of Illinois and their colleagues from Texas A&M University have been able to track specific genes in an infant's intestinal tract. They found that in newborns, this system undergoes significant changes in response to what the infant is fed.

Sharon Donovan, a University of Illinois professor of nutrition, noted that “for the first time, we can see that breast milk induces genetic pathways that are quite different from those in formula-fed infants.” She went on to explain that “the response to human milk exceeds that of formula, suggesting that the bioactive components in breast milk are important in this response.”

In the new study, intestinal gene expression was explored in 22 healthy infants, 12 who were being breast-fed and 10 who were receiving formula. The investigators isolated intestinal cells collected from the infants’ stools, which the mothers collected from their babies at ages one, two, and three months. Scientists isolated and turned their attention to RNA to uncover a gene expression or signature and found that breast milk invoked different genetic responses than did formula.

A healthy intestinal environment is critical for infants, whose immune systems are far from being mature. Donovan explained that “it’s very important that the gut learns what’s good and what’s bad. The baby’s body needs to be able to recognize a bad bacteria or a bad virus and fight it.” If something goes wrong during this early stage of development, infants can develop a variety of conditions, including food allergies, asthma, and inflammatory bowel disease.

The findings of this study will allow scientists to form a more complete idea of the activity in an infant’s gut and how the bacteria differ in breast-fed and formula-fed infants. Although the makers of infant formula have attempted to make products that are close to breast milk, Donovan noted they found that “hundreds of genes were expressed differently in the breast-fed and formula-fed groups.”

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PregnancyWeekly.com

Although it might look like a baby is chewing on the mother's nipple, ultrasound images show that the infant actually removes milk by creating a vacuum - also known as sucking.

The finding is important, as it could explain why some babies fail to take to the breast. It may also shed new light on why - for a minority of women - breastfeeding really can be a painful experience.

"There have been two theories about how breast milk is expressed," says Donna Geddes of the University of Western Australia in Crawley.

"One is that the baby uses a peristaltic or compression motion to actually push the milk out of the nipple and breast. The other theory is that vacuum is primary in removing the milk."

Until now, most studies examining the mechanics of breastfeeding have focused on bottle-feeding infants, or on old X-rays that were of poor quality.

Instead, Geddes and her colleagues combined ultrasound imaging of infants suckling on the breast with measurements of the strength of the vacuum created by the baby's mouth in 20 infants aged 3 to 24 weeks as they breastfed.

"What we see is that when the tongue is lowered and the vacuum is applied, that's when the milk is coming out of the breast, and that doesn't involve any compression of the nipple," says Geddes. "It's not a milking action at all."

They also found that infants who struggled to breastfeed generated much weaker vacuums than successful breastfeeders. This may explain why babies with a cleft palate often fail to breastfeed, as do premature babies: preterm infants don't have strong enough mouth muscles to suck hard enough.

The next step is to devise a simple and universal test that could be used to assess babies' ability to suck. This could reassure mothers whose infants are struggling to feed that it's not their fault. "Currently there are no measurements to assure the mother or the clinician that things [in the breast] are working," says Geddes.

For such women, keeping the milk flowing using a breast pump and using this to top up breastfeeding until the baby is strong enough to suck effectively may be a better option than giving up on breastfeeding altogether.

The team also looked at women who found breastfeeding painful and discovered that their infants had a particularly vigorous action.

"They're strong suckers," says Geddes. Some were also distorting or crushing the nipple. Further study of these infants may aid the development of better nipple shields to reduce pain during breastfeeding.

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PregnancyWeekly.com

Among twins whose weight differs markedly at birth, the heavier child is more likely to have conduct problems at ages 3 and 4, a new study finds.

"The findings suggest an effect of birth weight differences on development of subsequent conduct problems," researchers led by Dr. David Mankuta of Hadassah Hebrew University Hospital in Jerusalem, said in a news release. "Further studies are needed to clarify the mediating factors of this effect."

The team studied 112 pairs of Israeli twins in which one weighed at least 20 percent more than the other. The twins were born in 2004 and 2005.

The researchers found that the heavier twin had more conduct problems in 41 percent of the twin pairs. The twin who weighed less had more conduct problems in only 21 percent of the cases.

The study findings were published in the May issue of Archives of Pediatrics & Adolescent Medicine.

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PregnancyWeekly.com

Type "pacifiers" into Google and it immediately asks a common parenting question. "Pacifiers: Are they good for your baby?"

I thought no. Isaiah thought yes. And if he could type, he'd put that "yes" in italics and all caps.

From the moment my son was born, the one and only thing he asked of the world is that it give him something to suck. Isaiah sucked -- poorly -- on his thumbs and fingers and -- expertly -- on dirty laundry, stuffed sheep, our necks, other people's noses. If we had put lumber in his bassinet, he would have sucked it down to driftwood.

Like all newborns, he was a body led around by a mouth. "Sucking is a predominant activity during the first 6 months of life," as the infancy scientist Tiffany Field has written, "just as walking is the predominant milestone at 1 year." It starts early: Ultrasounds frequently capture fetuses sucking on their extremities; babies are born tattooed with sucking blisters.

Sucking was what Isaiah was born to do. So why did I feel wracked about giving him a pacifier? He wasn't wracked about taking it; he thought multicolored silicone was delightfully soothing. And it wasn't just me who felt uncertain about it. Even Google's algorithms knew we didn't know what to make of pacifiers.

Strangely, our contemporary anxieties about pacifiers likely have less to do with the actual objects -- recent research suggests they're helpful, not harmful -- than with their twisted modern history. We've inherited over a century of medical hysteria about infant sucking. No wonder pacifiers get us all worked up.

Psychologists immediately drew a parallel between sucking, with its world-obliterating intensity, and drug addiction; indeed, many concluded that all addiction was sublimated sucking. In 1925, the American psychologist James Mursell went so far as to argue that "the drive behind the smoking habit cannot be due to the specific effects of tobacco as a drug, for these are negligible in any case." The ultimate effects of alcohol and tobacco, he concluded, are "largely fictitious." Sucking was the true menace.

It's a fear that sounds at once far away and close by: Too much sucking is bad. For some reason. Really. Trust us.

Paradoxically, though, the bulk of contemporary research into pacifiers is not about their dangers. It's about their benefits. Premature infants who are given pacifiers mature faster and leave the hospital sooner: Non-nutritive sucking is now a standard part of preterm care. Pacifiers are highly effective pain relievers, dramatically reducing crying during painful procedures like circumcision. They -- somewhat mysteriously -- reduce the risk of SIDS: The American Academy of Pediatrics, in a highly controversial decision, now recommends pacifier use at night and during naps. The pacifier entry in a recent book on infant development includes this unconditional assessment: "Pacifiers provide comfort, promote physiological tranquility, and help in growth and development."

It's a confusing verdict: It seems unequivocal. Things can't be that simple, can they? And according to many doctors and lactation consultants, they aren't. This entry only tells half the story: The real problem with pacifiers is that they impede breast-feeding -- the flimsy, fake nipple confuses the infant and disturbs the natural rhythms of nursing. Weaning soon follows.

In fact, UNICEF/WHO's influential Baby-Friendly Hospital Initiative requires that hospitals "[g]ive no pacifiers or artificial nipples to breastfeeding infants." It makes intuitive sense that pacifiers would disturb breast-feeding. But evidence for it is underwhelming. The best studies on the question conclude that pacifiers, at least if given 15 days after birth, have no effect on the duration or success of breast-feeding. Nipple confusion, for that matter, may simply be a myth. A recent review of the literature concludes that "[p]acifier use should no longer be actively discouraged and may be especially beneficial in the first six months of life."

But there's real reluctance to acknowledge evidence in favor of pacifiers. The current edition of "Breastfeeding and Human Lactation," the standard reference for lactation consultants, says, flatly, "Pacifiers undermine exclusive breastfeeding for the first six months." Negative studies are cited; positive studies are ignored.

Isaiah sucked on pacifiers compulsively for a few months. But after they began ruining his sleep -- he'd wake up when they fell out -- we broke him. And after a day, he hardly noticed. He didn't need to suck so much anymore. He'd changed. And we'd survived.

If pacifiers are benign, or even beneficial, it is hard not to feel that what permeates the contemporary pacifier debate is a fundamental distrust of parents: the fear that pacifiers will allow parents to detach themselves from their children -- to substitute a cold, industrial object for warm skin and sweet whispering and a steady heartbeat. But I'd like to think that while Isaiah used a pacifier, we had more of ourselves to give him: Screaming exhausts parental love; it doesn't strengthen it.

Of course, the current research on pacifiers might turn out to be flawed. Or maybe too many parents will rely too much on pacifiers. Or who knows. But until any of that happens, it'd be nice for parents -- at least for parents like myself, people who are instinctively, mysteriously allergic to the idea of pacifiers -- to be told that their decision might not much matter. For too long, how babies suck has mattered way too much.

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PregnancyWeekly.com

Talking has a bigger impact on their developing minds than other sounds, even musical ones, according to a new study.

Infants as young as 3 months old who were exposed to words, not baby talk, were more capable of "categorizing" pictures than babies who just listened to tones.

"For infants as young as three months of age, words exert a special influence that supports the ability to form a category," said Susan Hespos, associate professor at Northwestern University, according to the Daily Mail. "These findings offer the earliest evidence to date for a link between words and object categories."

The research, published in the journal Child Development, focused on 50 3-month-olds who looked at a series of pictures of fish. Either words or beeps were played as the babies looked at the photos. Next, they were shown photos of a fish and of a dinosaur, side by side, as researchers checked to see how long they looked at each photo. Apparently, when the babies looked at the fish longer than the dinosaur, this meant they had already categorized the fish in their minds.

The results, according to the researchers, were "striking." The babies in the "word" group kept their eyes on the fish for a longer period of time.

Sandra Waxman, a co-author of the study, said, "We suspect that human speech, and perhaps especially infant directed speech, engenders in young infants a kind of attention to the surrounding objects that promotes categorization."

Babies as young as three months old can even benefit from having stories read to them, says Dr. Albert Levy, assistant professor of medicine at Mount Sinai School of Medicine. "I don’t encourage parents to talk baby talk to their baby all the time because when you do, the baby learns to speak that way. Use the words you want them to learn."

Just a year ago, Hespos was involved in a study that demonstrated that babies are brainier than was previously thought, according to The Sun. The research found that babies as young as 5 months old learn by themselves, rather than by being taught. In that study, researchers showed the infants a tilted glass filled with blue liquid, and then a glass containing a blue solid that had been angled to look like the first glass. The babies looked at the solid longer than at the liquid, which meant they could tell the difference between the two.

"Babies are collecting data all the time," Hespos said.

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PregnancyWeekly.com

A new study suggests that our brains develop specialized circuits to process human voices long before we learn to speak.

The study, which appears in the journal Neuron, looked at brain activity in 32 infants as they listened to recorded sounds. Half the children were 4 months old and the other half were 7 months old.

Some of the sounds they heard were nonhuman sounds, like chickens clucking, a bell ringing or a cuckoo clock. The rest were clearly human utterances including some words, though not in any language the children would have heard before.

While the children listened, researchers from Germany and the U.K. measured activity in certain areas within a part of the brain called the superior temporal cortex, which is just above the ear. Other studies have shown that these areas are where voices are processed in adults.

In 4-month-old infants, these areas did not differentiate between human voices and nonhuman sounds, says Tobias Grossman from the Centre for Brain and Cognitive Development at the University of London and the Max Planck Institute for Human Cognitive and Brain Sciences.

But it was a different story in the 7-month-old infants, Grossman says. The brain responses showed that "they process human voice distinctly from other kinds of sounds," he says.

The researchers wanted to know whether the older children's brains would also respond to the emotional meaning that's often conveyed through vocal intonation.

So they played unfamiliar words spoken with happy, unhappy and neutral intonations, and once again, certain areas of the brain seemed to know the difference.

The findings provide strong evidence that specialized voice processing in the brain develops sometime between the fourth and seventh month of life, Grossman says.

Problems with the brain systems that recognize and process human voices could offer an early warning of language difficulties.

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PregnancyWeekly.com