Parents' Effects on the Brain

Early experiences, both positive and negative, shape our brains and those of our children. Brain scans are beginning to show more precisely just how much brain development is influenced by early life events and interactions.

Over the years researchers have looked for the most significant types of early experiences, the time periods best suited for optimizing certain brain developments, and the parts of the brain most affected by early experiences. In the process, they have gained insight into how positive experiences, such as support and nurturing, and negative experiences, such as abuse and neglect, affect brain development.

The hippocampus has emerged as one of the main areas of activity during brain development. Located deep in the brain, the hippocampus is involved in consolidation and retrieval of memories, as well as emotional functioning and spatial orientation. It seems to serve as a link between emotions and the senses and is likely why, for example, certain smells can prompt such vivid memories.

The hippocampi are two small, curved structures, one on each side of the lateral ventricle that together make up the hippocampus. Because it is dense with receptors for stress hormones, the hippocampus is very much affected by hormonal reactions to stress.

The better quality maternal support a child had, the researchers found, the larger and more developed their hippocampi were.

It is known that adults who have been abused during their childhoods have smaller hippocampi. However, until recently, there were few studies examining this relationship prospectively — starting in childhood and going forward. Recently, however, research published in the Proceedings of the National Academy of Sciences addresses this gap.

Investigators from Washington University in St. Louis wanted to see if having supportive caregivers affected children's brains, specifically, on the growth and development of the hippocampus, and what, if any difference this made to the children's and adolescents' ability to regulate their emotions.

When the hippocampus is smaller than normal, there is a risk of poor responses to stress, ineffective coping and some psychopathologies. In other words, the growth and development of the hippocampus is important for healthy emotional functioning throughout the life cycle.

The Washington University team followed 127 children. They observed the kind of caregiving they received and how well they handled their emotions. They also took neuroimages of each child's brain at three points in time between the ages of 7 and 13 years to measure the size of the hippocampus. These images were correlated with the measures of maternal support that were done during the same preschool and school age intervals.

Young teens who had shown the greatest hippocampal growth were better at regulating their emotions.

For example, in one of the waves of the study, preschoolers and their caregivers engaged in “the waiting task,” which required the child to wait for eight minutes before opening a brightly wrapped gift sitting within arm’s reach while his or her parent completed questionnaires. This was designed to be mildly stressful for both parent and child, and trained raters scored them based on the supportive caregiving strategies the parent used to help regulate the child’s impulse to open the gift before the appropriate amount of time had elapsed.

The better quality maternal support a child had, the researchers found, the larger and more developed their hippocampi were. Early childhood (preschool) was a particularly critical period. Mothers' support had an especially powerful impact on their preschoolers' hippocampal growth.

The researchers also measured the children's emotional regulation in early adolescence and found that young teens who had shown the greatest hippocampal growth in early childhood were better at regulating their emotions, suggesting that parental support during preschool leads to more emotionally competent adolescents.

The findings suggest ways children's brain growth and future emotional well-being can be nurtured and protected, and send a powerful message to parents, teachers and those who care for and about children. They also give substance to concerns about the impact abuse, neglect and psychosocial stressors such as poverty, hunger, or parental and personal illness have on children and teens' emotional development.

Given the critical period that exists for brain development among preschoolers, the researchers hope their findings may be used to inform programs for early identification and intervention of young children and families at risk.

Supporting and educating parents, caregivers and children, especially during the preschool years, can have a lifelong impact on the brain and children's ability to handle stress. In fact, the authors suggest that a cost effective public health approach to promoting a more physically and emotionally healthy adolescent and adult population should involve helping new mothers so they can better offer the emotional support their young children need.