A baby is not a blank slate at birth. Our human evolutionary heritage equips newborns with a range of behaviors that help ensure their survival, such as rooting for a breast and sucking, as well as basic physical reflexes. These earliest behaviors, in terms of neurological location, are mediated by the subcortex, a more primitive part of the brain that develops early and controls vital life functions. Infant development, explains Claire Kopp, is a process by which more and more of these behaviors arise from the higher-level region of the brain called the cortex.

A good example of how the control of behavior will shift within the brain is vision. “We have known for decades that 3-month-olds are more visually alert and socially responsive than 1-month-olds,” explains Kopp. “Now, with recent brain research we have learned that visual attention in the first weeks of life is largely due to activation of subcortical neurons and pathways. After this age there is an increasing shift to activation of cortical neurons and pathways.” As the behavior matures, it utilizes higher-level processing areas of the brain. “The cortex is essential for human thinking, language, emotion control, behavioral inhibition, and more so this shift is truly important.”

In the first year of life, we know that a baby’s brain triples in size (interestingly, most of the growth is not the creation of new neurons, but rather new connections). During this stage of rapid central nervous system growth, the brain uses more than half of the total energy consumed by the infant. We also know that biology and experiences work together, says Kopp, that human beings are impressively adaptable, and that every baby becomes a unique individual.

“The study of babies and toddlers’ development is the study of change,” says Kopp. That sounds simple. But in everyday conversation, Kopp adds, the word “development” can have different meanings. Even for scientists, there are different ways to think about development: we can view development as an event, a stage of progress, or a description of a process; we can examine development from genetic, environmental, and social perspectives; and we can look at the physical, psychological, and emotional components of development. Better yet, says Kopp, we can look at development in all of these ways.

But that can be daunting for scientists, let alone parents. “There are so many dimensions of change in the first 2 years that making sense of them might seem difficult,” acknowledges Kopp. “On the one hand, human infancy represents the beginning of great potential for learning.” But there are also obviously constraints on what a baby can learn and the timeframe in which that learning can happen.

It is actually the baby’s neurological immaturity, however, that enables the infant to focus on what is most important. A baby’s hearing abilities, for example, are limited, but they are limited in ways that make perfect sense: babies have ears attuned to the sounds of human voices. Recognizing these limits, says Kopp, also helps mothers and fathers support and find pleasure in the interaction and experiences that are important at each stage of their babies’ development.

Growing Awareness
An infant’s development is a continuum and attempts to subdivide it are somewhat arbitrary, but among the basic categories that developmental experts use are:

• Attention. An infant must work hard, neurologically speaking, to pay attention. Even more difficult is the ability to disengage from stimuli, which is why this comes later in development.

• Cognition. The behaviors that are classified as cognition, says Kopp, include memory, problem-solving skills, comprehension, and learning. “In effect, cognition is the shorthand word for knowledge, how knowledge is acquired, how our thought processes transform knowledge, and how we remember what we have learned.”

• Sense of Self. The development of an identity is a gradual, but orderly process, says Kopp. First comes a basic “recognition of the body,” followed by a growing “awareness of feelings and capabilities,” and then “self-evaluation.” At 3 months a baby’s sense of self is rudimentary, “but after the baby’s first birthday the development of self is helped along primarily by two factors: parents and the advent of increased language production skills.”

• Social Development. The growing interaction between baby and others is very much a social conversation. Babbling and smiles are important elements, of course, but also, at around 9 months, frowns that convey baby’s disapproval or unhappiness.

There are important milestones throughout the early months. In a number of learning areas, however, 3 months is “a major transition point,” says Kopp. Babies show the emotions of pleasure, interest, and boredom and have active memories. And they are just getting warmed up. Between 4 and 7 months, “babies celebrate the emergence of a whole new dimension of being,” according to Kopp. “These changes transform the baby from a primarily physical person with a few hard-earned motor and social skills into a more mentally alert, sociable individual who is busy ‘doing, thinking, and feeling.’” And they appear to know it. “Babies seem to revel in their ever expanding mental abilities,” says Kopp. “Being able to initiate social interactions also delights them, and they try to keep these exchanges going.” At this point, the baby knows he can make things happen.

At every point in development, of course, mom is not just a witness, but also an active participant. Consider even the simplest games of imitation. In the 1970s, psychologist Andrew Meltzoff demonstrated that infants could imitate facial gestures made by another person. Meltzoff would stick his tongue out at babies, for example, and they would promptly return the favor. It was a remarkable finding because the babies could not see or know whether their imitations were accurate. And yet they were.

Mirror Neurons
Twenty years later, researchers discovered in monkeys a neurological phenomenon that might explain such imitation: mirror neurons. These are neurons in the brain of an observer that mirror, or automatically imitate, the firing of neurons in the brain of someone else. Monkey see, monkey do. It is uncertain at exactly what age mirror neurons are fully operating and there are many things yet to be learned in how they work. But scientists increasingly believe that mirror neurons are involved when we empathize with others. In a sense we neurologically “share” their pain or joy. Mirror neurons, some researchers believe, may be at the heart of what human beings do uncannily well: understanding what might be going on in other people’s minds, understanding their intentions and motivations, in essence, “reading” their minds.

We put ourselves into the “mental shoes” of other people every day. We are all mind readers; we just don’t notice we are doing it. Trying to imagine how an infant “learns” to do the same can help us realize just how remarkable a feat it is. And in fact, some researchers believe that deficits in these abilities may help us understand some social communication disorders such as autism.

We have long known that a baby’s relationships are critical to healthy growth and development. And recent research may give us exciting new insights into the mechanisms that are shaping brain circuits in infancy. The basics are not likely to change, however. Brains and bonds are built over time. Loving, sensitive, and supportive relationships will continue to provide a strong foundation for both and the lifelong learning they make possible.

More on this topic

Mother-Baby Bond: The Biology of Love (VIDEO)
Mother-Baby Bond: The Biology of Love
Establishing New Life
Nurture & Protect
Growth & Sensations
Adapting & Anticipating
Joyous Mom, Joyous Baby
Your Baby Enters the World
Nourishing Body & Bond
Mother & Teacher
Nurturing Development
A Mutual Gaze
From Bump to Bundle

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Infant Nutrition Health Center, Mother-Baby Bond Health Center, Mother’s Milk Health Center, Monthly Infant Development Calendar Health Center,Weekly Pregnancy Calendar Health Center