How Early Events Affect Growing Brains
An interview with Neuroscientist Pat Levitt
Like your colleagues on the National Scientific Council on the Developing Child, you see a gap between what the science tells us and what our public policies aim to do. Where do you think this gap is most pronounced?
As a general matter, I believe our public policies underestimate the overwhelming influence of early experience on brain development. And that gap is reflected in the way we prioritize our national resources. If you add up the dollars we put into intervention programs like drug and alcohol abuse and criminal remediation, for example, and compare that to what we invest in early environmental supports that promote positive social and emotional development—I don’t know what the exact ratio will be, but it will reflect an enormous gap with our scientific knowledge base. We know from the scientific evidence that the greatest impact we can have is to invest very early, during these sensitive periods when the brain is most plastic or malleable. Yet we continue to invest economically in people at a time when it becomes more and more difficult to make a difference and to alter their life trajectory. Unfortunately, it’s as if we’ve taken the approach that we’ll just wait until the problems occur and then try to “fix” them. Well, from a neuroscience perspective, that’s exactly what we don’t want to do.
The field of neuroscience is advancing at lightning speed. What do we know today that we didn’t know a few years ago, and how has that affected your work?
Some of the most important advances involve the way we can now literally watch the brain in action. For example, neuroscientists have used experiments with animals to identify some mechanisms [to ascertain] how a toxic stressor—say, poor maternal care—actually changes the architecture of her offspring’s brain. And we can see the way it cranks up the stress hormones in the animal’s body as it is developing. In the work we’re doing here, I can identify how early experience changes the brain’s neurochemicals, and how the changes affect the way the brain functions. I can identify specific genes that change; I can even identify how those specific genes are modified over the course of this process. Taken together, that lets us tell you how early negative events actually get built into the growing brain.
We’ve sort of punched through to the “black box” [to use an aeronautical investigator’s terminology] and uncovered a lot of important mysteries as a result. And a lot of this has happened in maybe the last five years—since the late 1990s. Before then, we could only observe that a child was exposed to severe stress and the brain seemed different as a result, but we couldn’t draw a direct causal effect. I think the real breakthrough has come with our ability to monitor brain changes with specific experiences. At Vanderbilt, a colleague is studying patterns of brain activation in children—using some of the same “hot spot” technology you’re familiar with from the Weather Channel—to watch what happens to the brain as an intervention occurs for kids with math and reading problems. It provides a window into what’s happening as the child thinks and reasons through a problem.
If information like this [continues to be] produced in the next ten years, it will be an incredibly exciting and promising field with implications for all sorts of domains and human disease.
The interviewer: Dorian Friedman is the policy editor at The American Prospect, a monthly political magazine, and a former associate editor at U.S. News & World Report. She has worked to advance beneficial social policies and effective communication strategies with the FrameWorks Institute, the Welfare to Work Partnership, and other nonprofit organizations. She is based in Washington, D.C.
For information about commonly used terms in Council publications, see Definitions.