Nurturing the Developing Brain Through Science
Better understanding babies' brains through research can help every child reach his or her potential.
by Lilly O'Donnell
If you want a country to thrive, you have to educate its children. This cause-and-effect equation has become a mantra of the Obama presidency; he's used it to push for more investment in the school system, and held education out as the nugget of hope to fight off doomsayers. But what if the key to a successful adulthood begins before elementary school, or even before pre-school? New science shows that humans learn more in the first five years of their lives than they do in any other period, meaning that if the focus on education doesn't start until kindergarten, we're already way behind.
"We can reduce the massive disparities that already exist when children enter school by intervening during the earliest stages of development," says Sonya Dougal, Director of Life Sciences Discussion Groups at the New York Academy of Sciences, one of the hosts of the fifth annual Aspen Brain Forum last November. The conference, whose theme was "Shaping the Developing Brain: Prenatal through Early Childhood," brought together foremost scientists in the field to discuss the newest discoveries about early brain development, as well as what can be done to ensure that all children get the nutrition and interaction they need early on to thrive mentally, socially, and emotionally later in life.
The first 1000 days of life—from conception to about two years—are especially crucial to developing brain function.
"A very wide range of extremely complex biological mechanisms take place during this period to transform an embryo into a healthy infant," explains Mireille McLean, Associate Director at The Sackler Institute for Nutrition Science. It's been established that this is a crucial period, but before researchers can recommend an exact diet for pregnant mothers and infants, or fully prove the importance of early intellectual stimulation, hygiene, and a stress-free environment, all of which appear to contribute to healthy, fully developed young brains, more research needs to be done.
"Deepening our understanding of the impact of both positive and negative experiences on the developing brain is an important first step towards promoting healthy early childhood development," says Dougal.
The Imitation Game
What we do know about the developing brain is fascinating, and sheds light on both natural tendencies, such as the desire to exaggerate facial expressions and actions when interacting with babies and young children, and societal constructs, such as the prevalence of interactive nursery rhymes and songs. Babies learn through imitation, and the work that Andrew N. Meltzoff of the University of Washington presented during an Aspen Brain Forum talk called "Neural and Cognitive Development and Plasticity" shows that at 14 months old, babies' brains react similarly to observing an action as to performing it themselves—showing just how important observing and mimicking is to the learning process. Studies also showed that babies' brains did not react the same way to recordings or DVDs as they did to face-to-face interaction, proving that children who are not spoken to directly by their parents or other adults will not learn as well as those who are.
Understanding how mimicking is involved in learning, and how the young brain understands itself through the actions of others, may even be the key to ending stereotyping, suggested researchers, who explained that school-aged children form their own identities based on their perceptions of how people like them are treated. It's common knowledge that adults need to set good examples for children, but the more we understand about the young brain the more evidence there is that our brains are truly formed by what goes on around us when we're young.
Of course it would follow that if the young mind is shaped by absorbing and mimicking the behavior of adults, the absence of adults can result in serious, long-term damage. Charles A. Nelson III of Harvard Medical School and Boston Children's Hospital highlighted the importance of early engagement with his work on severe neglect as part of the talk on "Social and Environmental Influences on Brain Development" at the Aspen Brain Forum. His long-running study of institutionalized children in Bulgaria demonstrated long-lasting effects, with institutionalized children showing far less frontal cortex activity than those who were not institutionalized.
"Babies' brains react similarly to observing an action as to performing it themselves — showing just how important observing and mimicking is to the learning process."
The importance of early intervention is represented in the fact that children who were put into foster care by the age of two showed improvement when retested at age eight, while those who stayed institutionalized did not. In discussion, questions were raised about the possibility of intervention for older children—whether it's possible to repair the damage done by early neglect—but Nelson said that it is unclear.
Nelson's work examines extreme cases of neglect, but even in less severe cases, children who get less interaction with adults are at a disadvantage. It's been shown in several studies that poverty has a negative impact on brain development. There are many inter-connected factors that are not yet fully understood.
An Uneven Playing Field
By age four, children from low socioeconomic backgrounds tend to hear 30 million fewer words than their better-off peers. Since it's clear that they won't learn more words if they don't hear more words, they're at a great disadvantage when they start school and their peers already know a lot of the words being used. In her teleconferenced introduction to the Aspen Brain Forum, Hillary Clinton discussed The Clinton Foundation's Too Small to Fail initiative, which promotes further research into early childhood brain development and aims to help identify interventions that can level the playing field, close the "word gap," and set kids on the path to success.
Dana Suskind at the University of Chicago Medicine discussed a new program, the Thirty Million Words Initiative, which she launched to teach parents about how important language is to development, and to help them make sure they're talking to their babies enough. The program uses a device to track how many words parents use in speaking to their babies, like a language pedometer, to test whether parents who understand the importance of language development talk more to their children. So far researchers have seen a significant increase from parents who participated in the program.
While language learning is important in and of itself, as a key to overall healthy development and success later in life, it's also integral to learning more about how the brain works in general, and how we learn.
"Children who get less interaction with adults are at a disadvantage."
Patricia K. Kuhl from the University of Washington studies the importance of social learning, how babies learn language, and the effects of language learning on their cognitive abilities. In their first six months, she explains, babies are receptive to sounds from all languages, but between six months and a year old, they focus on their own languages. Kuhl's work shows that perception of other languages can be reopened, but that human interaction is necessary; audio and video recordings did not have the same effect as an adult speaking in person. Knowing more languages leads to more cognitive flexibility, and extends the crucial period for language learning.
"If we can understand this magic infants are putting to work," Kuhl says of the ease with which young children learn second languages, "we may be able to put it to work later in life."
Further proving the importance of parental involvement and interaction, another study comparing the brain activity of institutionalized children to that of children who live with parents showed higher amygdala reactivity in those who spent time in orphanages. The experiment also showed that the connections between the amygdala and the prefrontal cortex were unusually mature in the institutionalized children—or that their period of heightened learning had ended sooner than their peers'. This indicates that parental involvement extends this crucial period.
Elucidating Neural Connections
It might be possible to recreate the highly malleable state of early brain development later in life, not only as it pertains to language, according to Takao K. Hensch of Harvard University. In a talk at the Aspen Brain Forum, Hensch presented his work, which shows that injecting an enzyme into the brain can inhibit the process that closes off cells and ends the so-called "sensitive period" of brain development. The ability to extend or reopen this period of development could open up a whole new world of treatments for brain injuries and developmental disorders. A clinical trial is currently testing this technique's effectiveness in restoring vision.
"...connections between the amygdala and the prefrontal cortex were unusually mature in the institutionalized children ... their period of heightened learning had ended sooner than their peers'."
There are risks, however, associated with stimulating this kind of growth of neural connections because it's not yet possible to fully control which parts of the brain will be affected, Hensch warned. There could be other risks as well, in this very new area.
Before researchers announce a cure for brain injuries, the initial, malleable state of the very young brain must be better understood. In many ways, the brain is the least understood part of the human body. Scientists are always working to understand it better, but much of it remains a mystery.
The field of brain-mapping is still in its infancy, but promises to exponentially expand our potential understanding of the brain. Ed S. Lein, from the Allen Institute for Brain Science, is building brain atlases that expand on the idea of gene sequencing, which can identify the genes that are involved in neurodevelopment by mapping gene expression across brain areas and stages of development. But the atlases cannot pinpoint the genes' functions.
Mouse brains are easier to map, simply because they're smaller and simpler, but the progress that Lein's group has made so far in atlases of the human brain show huge differences in gene expression in humans and mice, illustrating how important it is to tackle the daunting task of mapping the human brain itself, rather than trying to make inferences about it based on data gleaned from mouse brains.
The value of understanding the brain in its early stages of development is clear. It could be the key to leveling the playing field for children from disadvantaged families, to ensuring children enter school prepared to succeed and thrive, and even to curing brain injuries and diseases.
Research & Practice: Two Sides of a Coin
McLean, of The Sackler Institute, explains that her organization and others are working hard to identify where the knowledge gaps are and to stimulate important research to address them. "There are many urgent unanswered questions," she says.
"While things like adult interaction, hearing many words, eating healthy foods, and so on, are all important for development, doing all of these things in isolation, at different points in the lifecycle, is not enough to help children reach their full potential."
But putting existing, high-quality research into practice is also an important way to nurture and, in a sense, democratize, brain development. For this reason, The Sackler Institute, with support from a scientific advisory group, created a Call to Action and Policy Brief "Fulfilling Every Child's Potential through Integrated Nutrition and Early Childhood Development Interventions." It proposes five actions (see box below) to support early childhood development grounded in evidence-based research findings. The findings show that it's not just the delivery of evidence-based interventions that matter, but also the way the interventions are delivered.
While things like adult interaction, hearing many words, eating healthy foods, and so on, are all important for development, doing all of these things in isolation, at different points in the lifecycle, is not enough to help children reach their full potential. They must be done together for maximum effectiveness. According to the Policy Brief, integration refers to interventions that have all components delivered simultaneously to the same population, with the objective that they reinforce each other and are cost-effective.
"Integrating early childhood development interventions from education, health, nutrition, social protection, and other sectors provides synergies that allow humans to reach their full potential," says Rafael Pérez-Escamilla, Professor of Epidemiology; Director, Office of Public Health Practice; and Director, Global Health Concentration at the Yale School of Public Health.
The upshot is that Obama's elegantly simple statement is correct: if you want a country to thrive, you have to educate its children. But research shows us that the reality is more complex; a collective, scientifically informed approach to development is essential in the earliest years—even before formal education starts—if you want every individual child to reach his or her full potential.
Lilly O'Donnell is a freelance writer in New York.