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:

 
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.

Comments

[Tracy]

Oops! I don't think I signed off on that one...that was a Tracy post.

[Penny]

Oh wow! That's totally fascinating! Do they do experiments based on hearing as well? eg playing sounds, watching for baby's reaction, playing slightly different sounds etc?

[Laurel]

I'm confused about the headphones, since these are visual experiments. Shouldn't the parent be blindfolded? Otherwise couldn't they communicate changes they see on the screen to the baby with physical twitches or cues, unintentionally, a la Mr. Ed?

I hasten to add I don't doubt the general results of these studies, and I think babies are amazing and awesome, I've got a 6-month-old in my lap right now--I'm just puzzled--it seems confounding.

[Tracy]

@Penny! Great question and way to blow my next blog (only kidding). Yes, yes, yes. Lots of stuff done with hearing and some AMAZING findings. I'll be posting about this.

[Tracy]

@Laurel
Good question. Sometimes the parent is blindfolded, wears headphones or both. It depends on what the baby is being tested on (something visual, auditory etc.). But yes, the general idea is that input to parents should not affect the baby's responses. Thanks for clearing that up.

[caramama]

Absolutely fascinating! Thanks for sharing how they figure this stuff out. I had a general sense of how they did it, but the details of how and what are really neat to hear. And babies are just amazing creatures!