Here is the full transcript of pediatrician and epidemiologist Dimitri Christakis on Media and Children at TEDxRainier conference.
Listen to the MP3 Audio: Dimitri Christakis on Media and Children at TEDxRainier
I am a pediatrician, a researcher and a parent and I became those things in that order. And the reason the sequencing is important is because even though I was a doctor who took care of children for a while and I was a researcher who studied ways to keep them healthy, it wasn’t until I became a parent that I got interested in, some might even say obsessed with early learning.
It was 14 years ago when my son was born and I took a month paternity leave to be with him in his third month of life. And now in retrospect as a pediatrician I should have known better because I opted for the time when colic crescendos and I spent that month with him and snuggly bouncing on a big blue ball and watching more daytime television than I had in my life and noticed that he was actually interested in and as much as I’d like to believe that my two month old was following CNN as closely as I was, it was obvious to me that he wasn’t, and yet something about that experience was important to him.
Now why do these early experiences matter? The typical newborn brain is 333 grams and in the first two years of life, it actually triples in size, it’s an extraordinary period of brain growth, unparalleled over the life course. And you can see that here — here is brain growth over the lifespan and you can see how steep the rise is early on and it continues to grow until about age 20 and I’ll let you guys in the audience find yourselves over on the right there and see why you have such a hard time finding your car keys this morning.
Now we’re actually born with a lifetime supply of brain cells or neurons, that’s not what actually grows. It’s the connections between those brain cells, we call synapses, that account for that brain growth. And those synapses form based on early experiences. If you will, the mind is fine tuned to the world, the babies and habit and to give you an example of that, that you can all relate to any child born anywhere in the world can learn to speak any language fluently. But if she isn’t exposed to certain sounds early in the first few years of her life, she can learn to speak another language later but she’ll never sound like a native speaker. So baby born today in mainland China as amazing as it is can learn to speak fluent Mandarin but if she doesn’t hear English sounds early in her life she can learn to speak English later but as we all know we know such people, she’ll struggle making certain sounds, it wasn’t because she wasn’t born with that capacity, it was because her early experience didn’t condition her mind to learn them.
Now this graphic actually shows just that. What you see is the brain and you see the neurons and the synapses connecting them. We’re born with about 2,500 synapses; by age 3 we have 15,000 and then over time those connections are actually pruned in response to the external stimulation, the external world that we live in.
And to give you another example of that. This is the breathing pattern of a one-day old infant listening to music. And you can see here that he’s listening to Mozart and then Stravinsky is put on and then Mozart again. Now I show you this not to present some kind of an infantile critique of classical music but — and those of you in the audience who are classic music aficionados might have a hypothesis about why Stravinsky did this to his breathing pattern. But the point is — the point is that even at one day of life there is a discernible physiological reaction to what babies are actually hearing.
Now we know from decades of research that too little stimulation early on is bad for brain development. I show you here two PET scans. Now PET scans are measures of brain function; the brighter colors show more brain activity. And on the left is a PET scan of a normal kindergartener and on the right is a PET scan of a child who was raised in a horribly neglected environment. This is actually a PET scan from a child who was raised in a Romanian orphanage and was profoundly neglected early in life. And you’ll notice that the areas of his brain that show no activity at all, it didn’t develop as a result of too little stimulation.
Now this is a horrific example of too little stimulation and the untoward consequences of it. But the question we’ve had in our lab for some time is: What about too much? Is it actually possible to over-stimulate the developing brain or more appropriately to inappropriately stimulate the developing brain in ways that are actually not beneficial but harmful? And this is important, because we’re technology-izing childhood today in a way that’s unprecedented.
In 1970, the average age at which children began to watch television regularly was four years, like this cute little girl here. And today based on research that we’ve done, it’s four months. It’s not just how early they watch but how much they watch. A typical child before the age of five is watching about four and a half hours of TV a day; that represents as much as 40% of their waking hours, which brings us to Baby Einstein.