As an undergraduate student at SUNY New Paltz years ago, I once got a personal letter from B.F. Skinner. It came from his office at Harvard and I suspect it was part of his protocol to positively reinforce anyone who seemed to subscribe even minimally to his behaviorist perspective. From a brain development point of view, it turns out that Skinner and John Watson and Ivan Pavlov were correct: the neurons that we most repeatedly use are the ones that, through repetition and reinforcement, grow fastest and make the strongest connections. And they’re the ones we retain the longest. The reverse is also true – those brain cells we use the least make the weakest connections and are destined to be cleared out of the network in the periodic neural cleansings that regularly take place in our brains. This well-documented programmed cell death is called apoptosis. It’s responsible for the deaths of 50-70 billion of our cells every day.
This massive neural cell-icide has tremendous implications for mothers-to-be. In many ways the life trajectory of a child is determined to a great extent in the womb. This is how it happens. If a pregnant woman undergoes excessive stress during her pregnancy, her body will generate stress chemicals like adrenaline, noradrenaline and dopamine. This internal stressful environment in mom gets conveyed to the baby in utero and becomes a teratogen, something that causes a structural abnormality during pregnancy. As the embryonic brain is developing, it is recording this stress in the limbic centers, putting the necessary available neural resources into operation to deal with this stressful in utero environment. But this comes at a price. Because the stress centers are being actively and repeatedly triggered, connections in other parts of the developing brain are not being made in large numbers or strengthened in ways that they might be, such as in prefrontal development where self-control and command central are located, for example. This leads to a variety of ongoing problems, including literal brain cell disconnection which makes us more vulnerable to stress, and impairs the ability to form and maintain the human relationships critical for success and happiness, often all through our lifespan!
Shortly before birth, a sweeping apoptosis takes place, one that literally reduces the about-to-be-born baby’s brain by half! Guess which cells are killed off and removed and which ones are then allowed to remain? Right. In a stressful pre-birth environment, the brain cells most needed to deal with the stressful circumstances are the ones that are retained, and others with weak or malformed connections are programmed for an early death.
Because the brain is amazingly plastic, however, we are continually afforded an opportunity to right this unfortunate condition. It’s what allows child neuro-psychiatrist, Bruce Perry to demonstrate his work with kids like The Boy Who was Raised as a Dog – children who can barely talk, and who have missed other important developmental milestones – and end up having them graduate from college as happy, productive human beings. Here’s some of what Bruce recently had to say on Oprah:
“As you grow, the brain is essentially like a sponge. It’s absorbing all kinds of experiences. So if a child is not held, touched, talked to, interacted with, loved, literally neurons do not make those connections, and many of them actually will die.”
“Big, big ventricular spaces (show up in stressed out kids), which will impact sleep, regulation of anxiety, regulation of mood, whether or not you’re very happy or sad.”
“Simple things like eye contact, touch, rocking and humming can make all the difference to a baby. It makes neurons grow, it makes them make connections. Then, it makes the brain more functional.”
Building the Best Brains Possible
It’s really exciting to me to realize that there are a whole host of good things that happen when neural development and integration are optimized from the start. And that we are discovering what can actually work to accomplish that. Many are things we’ve long known – providing a safe, stimulating environment where stress is kept manageable and motivating, where apoptosis takes out those cells which serve us and our children least, all the while retaining those which serve us best. It reminds me of something mentioned in the recent presidential inaugural address: “Know that your people will judge you on what you can build, not what you destroy.” Whether we like it or not, from a brain-building perspective, I think we judge ourselves as parents for very much the same thing.