Category Archives: 3-4 months

Can You Hear That? Listening Study Yields Amazing Insights About Early Human Language

In response to yesterday's blog on clever techniques researchers use to get at the goings on of the infant brain, someone asked if the "habituation technique" I described with looking is also used with listening. If you missed that post, click here for a quick primer. The answer of course is YES!

I was going to post an example of a listening habituation study but if you read yesterday's post, you can probably figure out how that would go. Here, instead, is an example of a listening study using a different listening technique called "conditioned head turning". I wanted to include it because it is one of the more famous studies with mind-blowing findings (if you didn't already hear about it in the media), that have come from infant listening work. I hope you agree that it's incredibly cool!

Check it out:

The Scoop: All babies are born with the capacity to acquire language and which one (or ones) they end up using depends on which one (or ones) they are exposed to. So it's not so surprising that young babies can hear and tell the difference between speech sounds that us old folks can no longer hear e.g. Japanese infants can hear and discriminate between the "r" and "l" sounds in the English language more easily than Japanese adults. Interestingly, the paring down of your sound repertoire to the sounds in your language (s) of exposure happens around 10 months of age, just around the onset of language production. It's as though the brain is honing in on what it will need to find our way in the social world.

In fact, the evidence suggests that this "honing in" may apply to social stimuli in general i.e. not just language. Another study showed that young infants can discriminate between different faces of the same race, a phenomenon that holds for different races; Chinese, Caucasian, African etc. But by 9 months of age, they seem to lose that fine tuned ability and are best at discriminating faces of their own race!  Read: social input goes a long way to influencing our social perception. Here's a link to one of the relevant papers in case you're really curious.

Notice that the speech and face processing narrowing is happening around the same time? Why? Probably because it's more efficient to be finely tuned to the social environment you have to deal with, the one you need to find your way in, to have your needs met in etc.

I don't know about you, but after reading this stuff I usually have two reactions: 1). Wow! Fascinating! and 2). Holy crap it's so much responsibility raising a child. What is he being exposed to?  Do we educate bilingually?  Is he getting multiracial/multicultural input?  Is that necessarily good or bad or something I should worry about at all?  Ughhh!  Then I usually realize that time is marching on and stuff is happening anyway, like it or not. There's only so much we can control…

- Tracy

What’s going on in that sweet little head of yours?

Ever look at your baby and wander what the heck is going on in that head? Ever read those articles in magazines or newspapers or hear stuff on the radio about scientific studies on human infants (non-medical) and wonder "How the heck do they know that?".  Can't exactly ask the baby. Heck, they hardly stay awake long enough to find out anything anyway, even if they could talk.

This week I thought I'd take you behind the scenes of infant research to give you a peek into how scientists get inside that head. In a nutshell? They take advantage of the things that babies already like to do such as suck, listen to and look at new things. Looking has probably been explored the most. And dude, you'd be amazed and what we've learned from theses studies.

Looking studies typically use something called "visual habituation". The set-up looks something like this:Dadandbabycb

Mum or dad wears a pair of headphones, so they can't nudge, budge or influence baby's behaviour in any way (like try to make them look especially brilliant- kidding, kidding…). Baby is given something to look at on the screen (image, video etc.). At first the baby is interested and looks intently ("Hey, what's that?!"). But eventually, baby gets bored and starts to look away – "That again, whatever…" We say that the baby has "habituated". Then the display changes and baby sees something new. If they look with renewed interest – "What the…?!" (we call this "dishabituation")- then we know that the baby detected the difference between the old and new thing. That's it.

Ho hum, you say. But get this, sometimes the change between the old and new thing can be VERY subtle (we're talking teeny-weeny). By tweaking these subtle changes – while keeping everything else in the displays the same – we've learned a whole host of things about what 's going on in that noggin'. And we're talking tiny babies (newborns, 1-month olds) right up to toddlers. 

Check out this example: In one study, 6 month olds who were habituated to displays of say 8 black dots on a white screen, looked longer when the display changed to 16 black dots. As the two displays contained the same brightness, density of dots, total area of the dots  (i.e. the amount of black), the researchers concluded that the infants must have detected the difference in number. We're talking 6 month olds here people, they're not counting (at least not the way we do)! Cool huh? 

Infant looking has been used to study everything plus the kitchen sink: we're talking awareness of spatial position, proportion, solidity of objects, understanding gravity, adults' intentions (did they mean to grab that object or just touch it by accident?), discriminating faces of the same race, sensitivity to facial expressions and even to rudimentary addition and subtraction (with some conclusions more hotly debated than others).  And get this: it takes longer for babies of depressed moms to habituate to a happy face compared to babies of non-depressed moms, presumably because it's more novel to them! 

Kinda makes you see that bundle of sweetness in a whole new light doesn't it? So what do you think? Are you surprised by some of these findings? Did you have other ideas about how researchers pried their way into the infant brain?  Wanna know about anything in particular about the baby brain? Send your q's and stay tuned to hear more about ingenious ways of getting at the inner sanctum later this week.

Three to four months old Part II: Reader’s question about sleep training a 3-month old baby

Here's a question from N., the gist of which represents a significant number of emails that I receive.

My baby is about to turn 3 months (currently 2.5) and I would love
to try sleep training.  I am very sleep deprived and it is causing
marital strife.  Our baby gets up at night every hour to three  and
sometimes he will only fall asleep while lying on us.  Naps are a joke
as they simply don't exist or, if the do, they are 5-45 minute catnaps
in my arms….there is no schedule.  I am not functioning well and it
is terrifying me!  I would like to try CIO when my baby turns 3 months
but I have a feeling that within 10min our baby will begin screaming
fits and my husband won't (right or wrong) go for this…he will only
let the baby cry for 5-10 ….I'm willing to go for much longer because
I am that desperate!
I can't wait an additional 3 months until the 6 month mark…any ideas or wisdom would so greatly be appreciated!

First and foremost, this is SUCH a tough age. I remember the panic I felt when I realized how much longer this whole infancy thing was going to last. At the time, I couldn't imagine making it "to the other side." A few thoughts: First, your baby actually does need to wake up at least a couple of times during the night to be fed. That doesn't mean she needs to wake up every hour for that nourishment, but it's good to keep in mind that the vast majority of infants need their stomachs re-filled every 3-4 hours or so. Second, you may find that your baby hits 3 months old and naturally starts sleeping longer stretches (and not necessarily on top of you either). These shifts may occur naturally, without you doing anything at all because those first 2.5 months are filled with huge biological changes that are settling down right about now. But if your baby DOES continue to wake up every hour or two and does not settle down easily afterwards and if you simply can't go on like this much longer, you can certainly consider some form of gentle sleep training methods.

As I mentioned in Part I of the 3 to 4 month stage description, this is the only stage that I am somewhat hesitant to recommend because the distress levels of the baby really do need to be monitored by the parent. But on the other hand, there are several reasons why we included this stage — in the book — as one of the
possible periods to sleep-train:
1. There are DESPERATE mothers like the one who posted the question who can't go on feeling sane without some change. I don't know this particular woman's circumstance, but many mothers also either need or want to go back to
work by the time their child is 3 months old. These mothers often have no
choice but to try SOMETHING. My main point is that if you feel you
have to do something, don't try sleep training at 4 months if you can avoid it and earlier than 2.5 months isn't wise either.
2. We have heard remarkably consistent reports from parents who did
gently sleep train (i.e., not CIO methods, more like "no-cry sleep
solutions") at this window with great success. Although I personally
didn't feel comfortable doing any kind of sleep training with my boys
this age (especially since they were 4 weeks premature and I had "issues", let's just say…), I strongly
feel that it's important to provide the developmental
and let parents make the decisions for themselves.
3. I think it's important to consider the unique properties of each developmental stage and think about whether there are some special considerations that should be made in terms of methods that might work best. From my perspective, I'd like to emphasize that whatever method is used
during this period, it shouldn't result in letting the baby cry for
more than 5-10 min max (I don't know about your baby, but mine cried
more than that if they were in their carseat and I stopped at a red
light). This is the only age at which I'm careful to dissuade parents
from picking a method that will involve prolonged distress because
the baby is simply biologically incapable of regulating intense distress by herself; she
needs mom and/or dad to bring her back down (of course, some babies DO calm themselves down at this age, but very few can do so when they are really, really wailing).

If you find that your baby doesn't take to sleep training easily during this age, and you feel you need to stop, then there ARE things you can do to maximize your own sleep. Some common suggestions: (1) Enlist your partner to take half the night shift and you do the other half. So, if you're breastfeeding, you can consider pumping or supplementing with formula and asking your partner to take the 10 pm – 2 am shift and you can take over for the 2 am – 7 am shift. That way, each of you are at least getting a 5-hour chunk of sleep in a row. (2) Hire a "mommy's helper" if you can afford it. This person can help soothe your baby to sleep after you feed her during the day and maximize nap times for you. She can also take your baby for a walk while you catch a nap. (3) Every 3 days or so, you can ask your partner to take the full night shift so you can catch up. Again, your partner can give the baby a bottle of breastmilk or formula when the baby wakes up. That way, you can always refuel twice a week and feel just a little more human. (4) If you can afford it, night doulas or night nurses that come very highly recommended can be serious life-savers when your partner can't help. Hiring someone even once/week might just give you enough energy to get you through the worst of this time. (5) Some people also find that co-sleeping during the worst of the frequent wakings works for them. It really DOES come to an end eventually and although 6 months seems completely impossible to imagine getting to at this point, your baby WILL get to that stage when sleep training may take much easier (believe me, I really DO get it, having had twin babies who woke up every other hour — and NOT the same hour — througout the first 6 months, I feel your horror like I was there yesterday).

What do you
think? Words of encouragement or wisdom for N.? Anyone out there who sleep-trained during this age and was
thrilled with the results (I know you're out there because I've talked
to many of you)? Does anyone want to respectfully gasp in horror at my
recommendation to try sleep training at this age?

Three to four months old Part I: (Maybe) the first window of opportunity for sleep-training

After all this talk about the dreaded developmental transition periods and why it might be best to avoid sleep training during these stages, it seems important to also start talking about the windows of opportunity. These are the ages and stages that children are more resilient, have less going on in terms of cognitive and emotional changes and they may be most open to changes in bedtime routines. For the next few weeks, I'll intersperse readers' questions about their sleep dilemmas with some posts about these more robust stages of emotional development.

I kinda, sorta hate to start with this first window of opportunity because I've got mixed feelings about it. It's the only "stable" stage that I suggest a lot of caution and leave the possibility of abandoning the sleep-training ship as soon as you start it if things just don't feel right. Your gut matters all the time, but with this young, young age, your sense of how your child is coping is perhaps the most critical. Not because I think horrible, irreparable damage is likely… more because, well, it's just a "feeling" I have. There you are, my totally ridiculous, patently unscientific reason for my ambivalence. But hey… the comments section on this blog are generally very sparse, so maybe this will incite some of you to throw some virtual rotten tomatoes my way.

There are some good developmental reasons why 2 1/2 months to 4 months is a safe window for some
people to sleep train their baby. It is a time when bodily habits, coordinated between mother and baby, have finally become consolidated, and the infant can now turn his attention to the most exciting things in the world outside his body: other people. Day and night cycles have become firmly established. At this age, babies are skilled at grasping, sucking, and gazing at objects and people for long periods. Baby-mobile This is why mobiles rock your 3 month-olds' world. But most importantly, this age is marked by the initiation of “reciprocal exchange” because it involves prolonged gazing at the mother and other family members who inevitably gaze back at the infant. Babies now gaze at mother, smile, coo, and delight in the ensuing changes in her face and voice. Mother, in turn, becomes fascinated by her baby’s facial expressions, especially smiles, and especially the smiles that seem to be a response to her own expressions and actions. As described by Daniel Stern, this feeling of being noticed, being important, being a source of excitement and pleasure for the baby, is a huge turn on to the mother, who gazes at the baby while cooing and gooing in exactly the way babies find most interesting (develpmentalists actually call this vocalizing "Motherese"). The baby notices mother’s gaze and sounds, as well as the changing facial expressions that accompany them, and seems to know intuitively that they are directed at him or her. This interpersonal connection is practically irresistible to most babies, who will stare at mother’s face for long periods while cooing and gooing. From about 2.5 to 4 months, episodes of mutual gazing stretch out longer and longer, and they become a fundamental source of excitement and joy for both partners. Scottish theorist Colwyn Trevarthen describes this as a state of “intersubjectivity” between the infant and caregiver (if you click on the Trevarthen link and are bored by the theory, scroll down and check out the pictures of parents and babies interacting… it might be interesting just to get a glimpse of how some of this research is conducted). There is a sense, not only of each partner responding to the other, but also of both partners sharing a world in which “we are here together.” The baby at this age is developing a secure sense of her environment, she's curious about her surrounds and can often calm herself down if not overly aroused. As a result, this may indeed be one of the first periods you can attempt some gentle form of sleep training.

Up next, a reader's question about how to regain her sanity after being sleep-deprived with her 3-month old. What are some of the unique considerations for helping these young babies sleep?

A reader’s question triggered this rant and I’m grateful for it

There are so many mixed feelings about sleep training (guilt, strident confidence, defensiveness, desperation, resignation, and so on) and I think, in part, it's a reflection of more general parenting philosophies. There are some of us that started out thinking that we'd be exceptionally responsive to our baby's needs and we'd give up taking care of ourselves for the privilege of taking care of an innocent baby. There are others of us who vowed to keep our own personal and professional lives while making reasonable compromises for our new baby. And still some of us went into this parenting thing with no clue that we'd have any "parenting philosophy" whatsoever until we saw that horrid woman with her sweet child and she… <you fill in the blank>. Somehow, many of us become so wildly committed to the paths that we chose explicitly or stumbled upon. Despite the wildly controversial issues that parents (mostly mothers) feel compelled to fight for (breast or bottle, daycare or SAH, CIO or co-sleep), the truth is that not much of it makes a reliable difference in the futures of our children. Short of flat-out abuse, neglect and SERIOUS conflict in the family context, most parenting is "good enough." And I for one am so grateful for that empirical fact.

I recently received the following question from a reader:

"We are new parents to a 3.5 month old baby girl. She is a delight,
but sleep (hers and ours) has been the biggest concern and biggest
challenge. As we consider what might be best for our daughter, we are
very curious to know if there are benefits to sleep training, or if
sleep training is merely not detrimental.
Our daughter goes down easily for her morning nap, semi-easily for
the mid-day nap, and sometimes will not go down for her p.m. nap
despite being tired, and sometimes exhausted. Once we let her cry on
and off for 45 minutes. It wasn't fun for us or her, but we
experimented to see if it might help her understand the concept of
Night sleep usually begins between 6:30 and 7 a la Weissbluth,
with a wake up between 1 and 2, and another between 4 and 5. She sleeps
in a co-sleeper and we're hoping to transition her to the crib at age 6

My short response is: you're doing everything right, your baby is following very normal sleep patterns, and I hope that the 4-month sleep transition doesn't make things harder. This really is a description of the average sleep pattern many 3.5 month olds experience. In response to the main question about whether there are benefits to sleep training (and not merely the lack of detrimental effects), no, there is no well-designed study that can answer your question. But researchers and consumers of research can use the data as they like. So… yes, good sleep has been consistently associated with better performance on complex problem-solving tasks, better memory, improved mood (decreased risk of depression) and better physical reflexes. But many babies suck at sleeping and this "suckiness" has NOT been proven to be associated with long-term negative outcomes. More to the point of the reader's question, being a "well trained" sleeper as a baby has not been shown to lead to any BETTER outcomes. That's because it is almost impossible to design the right study to answer this question rigorously. I'll save you the research methodology course that I suffered through, but suffice it to say that to really establish that there are actual long-term, IMPORTANT benefits to having been sleep-trained, you'd have to randomly assign parents to either sleep train their child or not, no matter their actual parenting philosophy, their own upbringing, their child's temperament, the amount of support they had in their lives, the necessity for parents to go back to work early in the child's life, and so on. In short, there's no ethical way to run such a study. So… what we're stuck with is a bunch of studies that look at some families that DO sleep train and some that DON'T. And guess what? These families don't only differ on whether they sleep trained or not. They differ on all the other variables that I just mentioned: parenting philosophy, family history, support, family structure, child temperament, and so on. And those factors have a complex, interactive effect on child outcomes. Some children's temperaments are easier than others and this makes some children easier to sleep train for some parents. For other parents, they don't feel the need to sleep train these children with easier temperaments. Both families and children fair well. You can see the problem when you then add all the other variables that I mentioned. In short, there's no ethical way to do this kind of science to answer the question absolutely.

So… what we do know is being a sensitive, responsive parent while at the same time setting reasonable limits matters for the long-term developmental outcomes of our children. So does being personally happy, emotionally resilient, financially secure, and happily married (or in a secure, non-conflictual relationship). And if we're none of those things, if we're financially stressed, a single mom, bouncing back and forth between depression and "ok-ness", we are STILL likely to bring up our children to be thoughtful, loving, resilient, motivated, successful adults. All the research I have read (way too much to link to here, but see the books I reference in the sidebar), reviewed, and conducted myself has led me and many others to the same general conclusion: We need to screw up BIG TIME to really put our children at serious risk for long-term negative outcomes. Oh, and BTW, we can also do everything "right" and still have children who take drugs, have unsafe sex, get arrested or end up sad and lonely at the end of their life.

Sleep training matters in the day-to-day way that parenting always matters. But we're all trying to do our best, working with what instincts we have and compensating for what we don't with as much reading and surfing the web as we can fit in. Most of us will muddle through because we care enough to do our best (yes, it sounds like a commercial and I am SO cheesy sometimes). And chances are, our kids will be just fine, no matter if we Ferberize, co-sleep, CIO, use "no-cry" strategies, or say to hell with all of this sleep training.