Increasing research has shown that child abuse or neglect during infancy and early childhood affects early brain development. The National Clearinghouse on Child Abuse and Neglect Information, in Understanding the Effects of Maltreatment on Early Brain Development (U.S. Department of Health and Human Services, Washington, DC, October 2001), defined "brain development, or learning," as "the process of creating, strengthening, and discarding connections among the neurons; these connections are called synapses." Neurons, or nerve cells, send signals to one another through synapses, which in turn form the neuronal pathways that enable the brain to respond to specific environments.
An infant is born with very few synapses formed. These include those responsible for breathing, eating, and sleeping. During the early years of life the brain develops synapses at a fast rate. Scientists have found that repeated experiences strengthen the neuronal pathways, making them sensitive to similar experiences that may occur later on in life. Unfortunately, if these early life experiences are of a negative nature, the development of the brain may be impaired. For example, if an infant who cries for attention constantly gets ignored, his brain creates the neuronal pathway that enables him to cope with being ignored. If the infant continually fails to get the attention he or she craves, the brain strengthens that same neuronal pathway.
Childhood abuse or neglect has long-term consequences on brain development. When children suffer abuse or neglect, their brains are preoccupied with reacting to the chronic stress. As the brain builds and strengthens neuronal pathways involved with survival, it fails to develop social and cognitive skills. Later on in life, maltreatment victims may not know how to react to kindness and nurturing because the brain has no memory of how to respond to those new experiences. They may also have learning difficulties because the brain has focused solely on the body's survival so that the thinking processes may not have been developed or may have been impaired.
Hyperarousal is another consequence of maltreatment on brain development. During the state of hyperarousal, the brain is always attuned to what it perceives as a threatening situation. The brain has "learned" that the world is a dangerous place, and it has to be constantly on the alert. The victim experiences extreme anxiety at any perceived threat, or he or she may use aggression to control the situation. For example, children who have been physically abused may start a fight just so they can control the conflict and be able to choose their adversary. Males and older children are more likely to exhibit hyperarousal.
Researchers have found that, while males and older children tend to suffer from hyperarousal, younger children and females are more likely to show dissociation. In the dissociative state victims disconnect themselves from the negative experience. Their bodies and minds do not react to the abusive experience, "pretending" not to be there.
Childhood maltreatment can result in the disruption of the attachment process, which refers to the development of healthy emotional relationships with others. Under normal circumstances the first relationship that infants develop is with their caregivers. Such relationships form the basis for future emotional connections. In maltreated children, the attachment process may not be fully developed, resulting in the inability to know oneself as well as to put oneself in another's position.