Category Archives: Baby Brains

More Tidbits on Memory…and a Clip You Can Watch WITH Your Kids

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 So many fantastic thoughts and comments lately. What a great readership! Some really interesting questions asked/points raised about memory. They jogged my own noggin' (noticeably on the decline in recent years) of a few related studies. Here are the nutshell versions:

1. One of the ways researchers get memory in people of all ages is to compare how easy it is to learn something for the first time, compared to when we have to learn it again. For example, in lots of traditional memory studies with adults, the researchers gave their participants lists of words or word pairs (sock-orange) and looked at how long it took to learn them. Then after some substantial delay, when the participants no longer consciously remembered the list, they brought them back and looked at how long it took them to learn the same list to perfect recall again. The difference in the time it took at time 1 and time 2 is termed "savings" which basically shows that you unconsciously retained or REMEMBERED some of the list. For more on this idea and the guy behind it try here

Of course, we're not going to give a baby a list of words to learn, but just think of the task in terms of something that babies CAN do. For example, in one study infants of just a few months were put in a crib and their leg was connected to a string (such as by a a loop around their ankle). The point was to see how long it took the baby to figure out that if they kicked that leg vigorously, something fun would happen (e.g. a clown doll would appear, or they'd hear a funny sound, the lights would flash etc.). Then after a delay, they brought the babies back and put them in the same crib, same set-up etc. If they got the "leg kick = funny event" link more quickly, the researchers would conclude that the babies REMEMBERED what they needed to do. Oh there's always a way to get inside that amazing baby head…

2.  The stuff you have to remember to do in future – take your medicine at 2pm, TAKE A HOLIDAY GIFT IN FOR YOUR CHILD'S TEACHER BEFORE THE LAST DAY OF SCHOOL (I'm just sayin'…) – is called prospective memory (as opposed to retrospective memory, for things in the past). It's one of the first things to go when you get older. That's your head's up. 

3.  Yes, there is such a thing as photographic memory – when you can picture in your mind the actual material you want to remember, in the place where you first learned it. That's as in, you are writing an exam and you can picture in your head the page in the text book where you read it AND YOU CAN SCAN THAT PAGE TO FIND WHAT YOU ARE AFTER. It's not exactly common. Usually fades by later childhood (11 or so). Any takers?  Did any of you do this?  I definitely relied on this in school, even later on, but it got way, way harder as the years went by. I'm not sure how good a measure of photographic memory this is…but if you have a few minutes on your hands (ha ha ha…) or insomnia, Try this

4.  Another favourite line of research (honestly, can I really call it a fave when there are so many?) specifically targets childhood amnesia. Here's a link to the primary researcher's homepage if you want to have a browse. I cannot help but highlight one of her coolest recent findings. Ya know how excited I get about these things…

The researchers visited young children (about 2-3 years of age) in their homes and taught them a novel event. A machine would actually "shrink" a toy you put inside it. Read: Child puts a big toy in the front opening of the machine, then closes the door. Some flashing lights and machine like sounds go off, then they open door and find a miniature version of the toy inside. Yes, of course, it's been replaced with the mini one by way of the back door and another researcher or something, but boy do they go for it!  It's amazing!!!. This all happens at an age when language is fairly limited but then develops amazingly quickly. They know because they actually measure the children's language skills. 

Then after 6 months or 1 year, they go back to visit the same children and basically probe to see if they remember what happened on that first visit, now "ages" ago as far as they are concerned. The probing includes asking them to talk about it (verbal measure), asking them to pick out pictures of e.g. some of the toys they shrunk (visual recognition) and asking them if they remember how to work the machine (behavioural re-enactment). And oh yes, they measure their language skills again. Get this: Even though children remember what happened (as shown by their performance on the visual recognition and behavioural measures – both non-verbal), their memories are limited to the vocabulary they had AT THE TIME the shrinking machine thing took place. That is, even though they now had WAY better vocabularies, they described the event only in terms of the language they had AT THE TIME THEY EXPERIENCED IT!  This suggests of course that our so-called infantile amnesia is linked to our limited capacity to code or store our experiences in words when our vocabularies are so very limited. Note that as the children had good non-verbal memory of the event, they clearly registered it. It's just that they were limited in their ability to access those memories verbally. So perhaps this helps to explain why we later can no longer access those early memories and integrate them into our autobiographical memories when we are older and rely more on storing and accessing memories verbally. Hmmm…

6. Finally, to help keep your internet-using guilt at bay and to end the week on a lighter note, here's a fun clip on memory that you can actually watch WITH your kids! 

Now just remember to watch it. Good weekend.


More on autobiographical memory: What do we remember from our childhood and why?

I was writing a comment back to the few readers that responded to the last post, part of which mentioned autobiographical memory, and then realized it was WAY too long for a comment and I might as well share it with everyone. So, here are a few more thoughts about the research on autobiographical memory:

In the comment section, @sheila asked some GREAT questions, the first of which was: How do scientists measure memories and trace them forward to deem them accurate or not? There are a bunch of ways that developmental scientists look at these things, some will seem pretty darn boring because it's not like you can ASK an infant if he remembers something. So, what researchers do is, for example, show a baby a shape one day and then test whether he "remembers" it a few days later by looking at his gaze and the extent to which it implies "recognition". Or they will teach an 18 month old a sequence of play events (hit this, then this, then pop goes the toy) and then test him at 2 years old and see if he knows how to re-enact that play sequence. Ta DA! Memory! If you look at the article I linked to in the last post, they give you a bunch of details (if you can't access it and are interested enough, leave a comment and I can send the pdf file).

Sheila also described the common experience of not being able to differentiate details of your childhood memories from stories or pictures that parents and other people tell you as you are growing up. This is indeed the norm in terms of how most people think of childhood memories. Interestingly, and not surprisingly, children DEVELOP the ability to remember in different ways. At first, young babies and children tend to "encode" small, concrete details about their world. Of course, that's because that's how they understand the world around them at that early stage of cognitive development — in concrete terms, not abstract. Also, their working memory capacity (the RAM of our minds) is so limited at this age that they can't keep much in mind at the same time for very long at all. As children grow, they are able to hold more in storage, to keep more things in the mind's RAM for longer periods of time. With that developmental progression comes older children's and adults' abilities to encode more "gist-like" or "fuzzy trace" memories. So, we as adults are more likely to remember episodes in terms of their general meaning to us, their emotional valance, and so on. Both children and adults "store" memories in both the more literal (e.g., details about a task, episode, etc.) and "gist-like"  (semantic, elaborate, "relational) styles, but young children rely much more on the former and adults more on the latter. (You guys don't want me to spout on about the fact that there actually is no "storage" per se in the brain, like a treasure chest that gets opened and shut; instead it's more about patterns of neural firings that scientists are still pretty in the dark about).

@Beth wondered in the comments whether early memories can be triggered by trauma; implicitly I thought she was also asking if more traumatic experiences are better remembered. Yes, to have ANY experience stick and become a lasting memory, there needs to be SOME level of emotion involved. There's a whole lot of cool neuroscience to back this claim up — but the summary is that you need certain parts of your more "primal, emotional" brain to be firing during an event to encode it into long-term memory. So it is indeed possible that those more emotionally-charged experiences are the ones you remember best. But also, those are the experiences that will be talked about most in your family oftentimes, which keeps those memory traces alive and these re-enactments, in turn, continue to strengthen those neural memory traces.

But there is also the extreme cases of emotional memories; these are the cases of post-traumatic stress disorder (PTSD). People with PTSD have experienced INSANELY traumatic things (abuse, war, etc.) and in some of these cases, their emotional centres OVER-fired and shut down the part of the brain that participates in storing information and forming memories during the trauma. As a result of this emotional flooding, these people often DON'T remember the traumatic events themselves (nice evolutionary survival mechanism, if you ask me). PTSD sufferers often have NO semantic memory (they can't actually remember WHAT happened), but they have EMOTIONAL traces still "stored." So, for example, a loud bang from a garbage truck can trigger seemingly irrational panic/anxiety attacks in a veteran who has experienced horrors in combat, but he won't know why because he won't be able to trace the memory back to the initial experience. (For more info, Joseph LeDoux has some exceptional research in this area).

@Cloud expressed something I think about almost daily right now, as I try to develop family traditions that my children will hopefully look back on with warmth and love throughout their lives: How WEIRD is it that a 2.5 year old (and many 3-5 year olds also) won't remember our vacations, holiday celebrations, or any other cool events, events that they can NOW remember? I think it IS strange. But also, we have to remember (hahahahaha… ugh) that just because most children won't retain coherent memories of these special events into adulthood, they still MATTER. These experiences still make up the foundation of who our children are, how they are developing, how secure, happy, anxious, angry, and so on they WILL become. We may not be able to retrieve a perfectly intact memory of our childhood vacations (I certainly can't), but those experiences nevertheless were the basis from which we learned how to share with other kids, swim safely, dance like lunatics, trust adults, stay clear of poison ivy, read with a watch light under the covers, try different types of foods, and so on. 

And now this post is getting away from me and I haven't even BEGUN to talk about all the ways in which our memories are biased, flawed, skewed, motivated by our current situation, mood, developmental stage and so on. There are boatloads of studies that show how bad we are at ACCURATELY encoding certain types of information. And who among us has not had the fight with a parent, sibling or partner who remembered a CRUCIAL event totally differently than we did? Memory is NOT an objective, factual trace laid onto our neural circuitry… that's what makes it so fascinating for so many psychologists to study and for so many therapists to delve more deeply into with their clients.

Are those experiences that we CAN'T remember from our childhood any less influential on the person we've become than the things we DO remember? What memories would you be/ are you sad that your child will not retain? (My mother, for example, is horrified that I don't remember the details of our trip to Italy when we were 12 years old. TWELVE?!?! How could I forget that gorgeous cathedral, that ice cream cone, that gilded br
idge?! She thinks I'm brain damaged. But the thing is, I DO remember the guy on the Spanish Steps who winked at me on his moped… 28 years later, and I remember him and that wink PERFECTLY.)

– Isabela

The Cat in the Hat in the Amniotic Sac: What Can Sucking Tell Us About Hearing?

Cat in the hat What's with the feline in the millinery?  As with yesterday's post, try not to shoot the blogger if you've already heard this one. It's an old study (early 80's – never mind that I can remember the time…just barely I'll have you know), but the media has gone wild with it ever since it first came out. I just could NOT think of a week of posting on methods in infant research without mentioning it. What about that title? Gotta love it!

This study used sucking to shed light on prenatal hearing.In earlier work, the researches had determined that very young infants would adjust their sucking rate to be rewarded with hearing their mothers voice (I bet this doesn't happen in the teenage years…but I digress…). Mothers read The Cat in the Hat Story or another one of two other stories to their unborn fetuses, 2x per day for the last 6 weeks or so of pregnancy. Soon after birth, the researchers measured infant sucking when they heard the story they heard prenatally vs. one of the other stories. What happened? The newborns worked hard (sucked faster or slower) to hear the story they heard in the womb – moreso than to hear the other story. By playing with this method a bit more, later work showed that it was the rhythm of the story and not the words that the babies were responding to. BTW, the babies also worked harder to hear mom do the reading over some other female voice reading the same story. This study was a real landmark in establishing at least a couple of things: 1). the state of development of hearing in the womb and 2). how the prenatal environment helps tweek perception. 

If you're now thinking "Wow, amazing how far these researchers will go", consider this: in another (now old) study a pregnant woman was asked to swallow a tiny microphone so that researchers could gain a better sense of just exactly what the baby can hear in there. Can you imagine it? "It's in the name of science ma'am. Please just please swallow the technology." 

So I'm on a roll now. Here's another interesting way that researchers have used sucking. The main question was whether information taken in through one sense (e.g. sight) is stored in such a way that it can be accessed through other senses (e.g. touch). The technical term is cross-modal or inter-modal perception. In one study, 1-month old babies were allowed to suck on either a smooth or a bumpy pacifier – but they were NOT allowed to see it. The babies were then shown two simultaneous pics, one of the smooth pacifier and one of the bumpy one. And guess what? They looked longer at the one they had sucked on but NEVER SAW, as though they recognized it. So what they had taken in through sucking or touch was stored in a more general way, a way that was accessible through another sense, sight.  

Finally, I wanted to briefly mention the use of "geodesic nets" – think "hairnets with sensors" that provide real-time information on the patterns of brain activity as the brain processes something e.g. a picture, a sound, an event etc. The baby wears a get-up like the one shown here. Newsweek Baby brain
It's not painful at all and many babies are surprisingly co-operative about the whole experience. For more on geodesic nets and language studies, put in user friendly terms, try here.

Phew. It's been a whirlwind tour through infant research this week. Now seems like a good time to ask how this stuff is all working out for you. Too technical? Nerdy? Boring? Less on studies, more on parenting connections?  It would be great to hear some feedback. I hope that even if the details were too much or we covered too much ground that you might have gained a new respect for that bundle of sweet-smelling, soft, cuddly goodness. That's one amazing brain growing in there!


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.

Friday Link Love: Brain plasticity

I'm thinking of the organization of the new blog (and writing a whole lot… I promise the posts will become much more frequent in the coming weeks). Now that the blog is going to be so much more broad in terms of its topics, I feel a little wiggy about how open-ended that leaves things. So… I'm thinking I need to be a little more structured about the TYPE of posts, if the CONTENT will be so far-ranging. Here's my first attempt at thinking about the organization of the week's posts. Of course, this may completely change as we get going here, but your thoughts are, as always, very welcome.

I'd like to start off with one theme every week. Many themes will be far too large to keep to just a week, but we can always return to them later or go for a few weeks on any single topic (for example, I can imagine that discipline could be a HUGE topic that would require more than a week and maybe needs to be organized by ages and so on). This Monday, I'll "introduce" you to my partner in crime who will be regularly contributing to the blog. But after the preliminary 2 weeks or so, here's what I'm thinking:

Monday: Theme introduction with a substantive post and some links to research (led hopefully by a reader's question, but I suspect at first, we'll call for specific questions about the theme that we can subsequently answer throughout the week).

Tuesday: Readers' questions about the theme addressed and a call for commenters' perspectives

Wednesday: Second substantive post about theme

Thursday: Um… not sure. We'll keep this open.

Friday: Link love. (There's always so many COOL sites I come across or great articles that I read online and I'd love to be able to share those with you. Since Friday is notoriously a slow-read day for many people, the links will allow people to visit the site on Friday or over the weekend and read more about whatever the theme of the week was. I'd like to include links to substantive articles, but also light-hearted posts by other writers, some videos, jokes, pictures and whatever else just seems to connect to what we're talking about).

So… here goes. The first Friday Link Love. Here are some cool articles I've been reading which are either directly or at least tangentially related to brain plasticity:

  • Here's a fascinating summary of a study published in Science that hints at new discoveries that will allow us to understand how new memories are formed (and what else is memory if it's not about  about "learning" after all?); how the brain is plastic enough to incorporate new stuff all the time, but all the while maintains some level of stability (so you remember who you are from day to day).
  • And here's the abstract (summary) of an article in Psychological Science about early language acquisition and how the brain "holds on" to these experiences, even when we're not aware of it. EVEN when we don't use the language anymore, as long as we learned it early in life, we still retain traces of those memories. SO cool (although not directly about plasticity as much as "stability").
  • Lastly, I leave you with two opposing pictures of the brain — one scientific and one more like how I'm feeling now, as the work-week comes to a crashing halt…

Thoughts, comments, reactions, criticisms, complaints or whatever else you've got, always welcome. Happy weekend, all.

What are they BUILDING in there?

 If anyone actually gets the musical reference to this title, I have found my new BFF (not that it has ANYTHING to do with what I'm about to talk about). 

So… let's consider this the first post of the "new" blog. If you don't know what I'm talking about, I'm going to be changing this blog to cover topics of all sorts in developmental psychology, not only sleep issues. The new look will actually take a few more weeks because I am a graphics dunce and completely clueless about blog design, so I'm hopefully getting some help with all that soon. Until then, let's just forge on and the pretty pictures around the posts will soon be more consistent with the actual content.


I've recently had a few emails asking about the effect of one thing or another on a baby's "brain" (for example, certain types of music, diet, lack of sleep). Neuroscience is so hot right now, both in the scientific world and the "lay person's" everyday world. There are tons and tons of new titles that seem to crop up everyday about how the brain is involved in all sorts of things we care about. I have a two-pronged reaction to all the neuroscience interest. On the one hand, I think it's great to integrate what we know about psychology, evolution, and biology, with what we could and should know about how the brain works. How could we go wrong with that general stance? On the other hand, I'm not all that starry-eyed about the results from brain research thus far on the most important issues in child development. In part, that's because we know SO VERY little about the most important processes in the brain and even less about those processes in children's brains. And I don't think we necessarily NEED to always go to what lights up in the brain to answer some of our most pressing questions about how children grow and flourish.

With that caveat in mind, let me tell you what DOES excite me about some developmental (child) neuroscience research. These ideas are not restricted to understanding children, but they're fascinating to think about in that context. 

Brain Plasticity and Development

The general idea is that all of us are born with a very "plastic" brain; one that can be, and is, shaped by our everyday experiences. This may seem really obvious to some people, but for a long time, many scholars believed that we are born with a done-deal sculpted brain architecture. But that is SO FAR from the truth. The actual structure of the brain changes over development (not only how it functions, which also undergoes incredible changes). Some parts of the brain thicken in some places, other parts thin out or stretch out and so on. Even more importantly, the connections between neurons in the brain grown and change over development BASED ON EXPERIENCE. These changes begin at birth but they keep going until well into adulthood. During
the first couple of years of life, about 700 new neural connections are
formed EACH AND EVERY SECOND (the connections are called synapses). At the very beginning of life, there's a huge outpouring of new connections that are formed but, over time, these connections
are reduced (a process called "pruning"… think about your bushes and you'll get a good sense of this). What's really cool is that it is by this pruning process that we become more efficient thinking machines (just like when you prune bushes to try to get more nutrients to certain parts of a tree more efficiently). There's been a whole lot of emphasis recently by developmental psychologists on how important it is to provide children with rich early learning environments (both in the home and in daycares and nursery schools) and this is because these early experiences lay the foundation for the circuits that will be strengthened and those that will die off. In short, if young babies and toddlers aren't provided contexts in which they use certain brain circuits, they'll lose them, or those connection will weaken considerably. This isn't as scary as it might sound though. The VAST majority of parents and teachers are already providing these rich environments.

Here's one of the take-home messages about brain plasticity (there are many, and some are absolutely incredible): Early experiences lay the foundation for later ones and the more "basic" connections get built up to more complex ones. So, for example, from the very simple sensory (sight, sound) experiences and physical experiences (coordinating legs and arms, thumbs and mouths), children build more complex cognitive skills that get interlaced with emotional capacities in this incredibly intricate web.

This is seriously only the very tip of the iceberg in terms of what we can talk about when it comes to the developing brain.  In the weeks to come, I'd like to show you some really amazing videos of the brain developing over childhood and adolescence and talk about what this means for how we structure our children's lives. HINT: I am not from the camp that believes you should be throwing a bunch of ultra complicated books, letters, numbers, Mozard CDs and French/Spanish flashcards at your babies so that their brains "develop" faster and more efficiently. In fact, playing (in its various forms of tickling, peek-a-boo, rattles, blocks, dolls, leggos, and so on) may be the best way young children develop the physical, cognitive and emotional skills they'll need throughout their lives.

If you're interested in reading more about brain plasticity (but not necessarily in the context of children), some of the better books out there, in my opinion, are Norman Doidge's The Brain That Changes Itself, Schwartz & Begley's The Mind and the Brain, Freeman's Societies of Brains, and Taylor's My Stroke of Insight (the last one I'm not happy with the "self help" aspect, but it's a FASCINATING story and the hard science is great).

So, what do you all think of this idea of brain plasticity? Is it sort of an obvious insight to you? Does it make you think differently at all about your little growing brain(s)? Does this stuff bore you to pieces? I realize that starting the first non-sleep post off with the brain is not the most "sexy" way to begin, but that's just what was on my mind today. What's on yours?