How the Brain Develops

CNN’s Chief Medical Correspondent, neurosurgeon Dr. Sanjay Gupta, explains how the brain develops.

Male Speaker: We are back with CNN's Chief Medical Correspondent Dr. Sanjay Gupta who most of you recognized from his on the scene reports from all over the world at some of the world's biggest natural disasters. But what many of you may not know is Dr. Gupta's Medical specialty which is? Dr. Sanjay Gupta: Neurosurgery. Male Speaker: And you know that something that lot of folks don't know and the expression well it isn't brain surgery. That exists for a reason so I am happy we have a neurosurgeon with us because the brain truly is your body's super computer that controls who you are, how you react to things, how your body functions? It's constantly evolving as we age and it does start at the very beginning when we are inside the womb. Dr. Sanjay Gupta: I love this stuff because it is really amazing how the brain develops and how early some of these changes start to take place just sort of back up and take a look. When you start, you are so -- it's just the few number of cells that this all starts with and then a rapid rate of growth that your brain starts to develop, they say two hundred fifty thousand new neurons a minute. And as you sort of really think about how the brain develops specifically you have all these neurons by the time you get to five or six months of development, you have got billions or neurons already and each of those neurons has about ten thousand separate connections and it's amazing because by the time a child starts to get older and starts to develop even further along, crawling, starting to walk even, starting to talk, they have billions and billions of neurons controlling all these functions in the brain and it's only about that age as you start to get full brain development. Male Speaker: And the crazy thing about a brain's development is, it doesn't matter what culture you live in, it doesn't matter where you are, your brain is going to develop similarly and slowly over time, you are going to become a teenager and what do teenagers do Dr. Gupta they react with emotion and what you are going to see here are some flirting teenagers, they don't tend to use reason and there is a reason for that. Dr. Sanjay Gupta: It's like they have no brain at all sometimes. You are right and amazing thing about the brain at this stage, I mean you really think about it is that the brain is sort of developing from the back to the front, so think of it like that. So all these areas at the back of the brain are starting to develop faster than the front of the brain. That is important because in this area over here, you have a lot of your judgment, your rational thought, your ability to think about things before you act so to speak and that hasn't fully developed in many teenagers, that's part of the problem over here and there are several different areas of the brain that are responsible for that, but that judgment part this is a big topic of discussion in the neural community, I mean should teenagers be allowed to drive if that of the brain isn't fully developed. There are people who say absolutely not, obviously in most places around the world they can, but it's really instinct, if you look at it like this. Male Speaker: So when a mother looks at her son and says sometimes it's like you are not even thinking, well they are not. Dr. Sanjay Gupta: She is absolutely right and there are other parts of the brain as well that you talked about what does govern your decisions if you don't have that ration thought well lot of times its an area right in here which called the Amygdala, its kind of your fear, your emotional part of the brain. But it's pretty well developed even before rational thought is developed. So this area over here teenagers will tend of think out of fear, out of more irrational thought, out of emotion as supposed to just good judgment. Male Speaker: And so constantly during this period the brain is going through changes right. Dr. Sanjay Gupta: That's right and so what would happens is the brain starts to literally prune itself, people who took lessons or learned a language for example as a kid if they stop doing that, just stopping taking lessons or stop doing the particular activity part of their brain will just sort of be pruned, I mean they will loose that function at some time. Male Speaker: So there is a neural-connection that governs that and when it prunes literally that connection will prune. Dr. Sanjay Gupta: Dies away, things you stop doing, you lose, things you keep doing you gain even get better at.