North American Ed - Brain development

2.2 Nurturing

An increasing number of more recent studies, utilizing brain imaging and other new technologies, now document the impact of nurturing, supportive interaction and ‘sensitive caregiving’ on both brain function and structure” (Center on the Developing Child at Harvard University, 2019, para. 2).

To really think about babies and how they develop, we have to think about who is taking care of them and the nature of the relationship(s). In the overview of this module, Dr. Stuart Shanker explained infants are “fetuses outside the womb” for the first nine months, completely dependent on caregivers for survival. We have also learned about the interactive nature of genetics and experience in determining how development unfolds. Clearly, the caregiver-child relationship is absolutely critical to early brain development and key to the child’s survival, health and development.

The next KidCareCanada video is an interview with Dr. Nils Bergman, a Swedish public health physician who has studied and worked in Zimbabwe and South Africa. He is perhaps best known as one of the founders of the Kangaroo Mother Care movement that promotes skin-to-skin contact between mothers and their newborns.

First and foremost, the physical and social environments young children experience are created and then mediated in relationships with adults who care for them. Before birth, the growing infant is sensitive to, and entirely dependent on, the uterine environment. After birth, infants remain dependent on adults for sustenance, physical care and love. Early caring relationships are a filter for experiences that drive the development of neural pathways involved in sensory perception, stress response patterns, self-regulation, language and intellectual abilities.

The National Scientific Council on the Developing Child reading that follows compares parent-baby interaction to the “serve and return” (or back and forth) aspect of a tennis match. This refers to the way a baby makes vocalizations and gestures that encourage adults to respond back in a similar way. This type of interaction supports healthy brain development. Be sure to read the section entitled “What Science Tells Us”.

In the next video, notice the connection between mother and baby.

Dr. Megan Gunnar, professor and former director of the Institute of Child Development at the University of Minnesota, describes her research on babies responses to receiving immunization shots in a doctor’s office. She explains how an infant’s secure attachment to a caregiver can act as a buffer for stress. Babies with insecure attachments to caregivers experienced a rise in cortisol, while those with secure attachments did not. On the next page in this module (2.3 Stress), you will learn more about the harmful effects of excessive cortisol elevation.

In the next video, watch as 7 month old Solange experiences a visit to the doctor.

Think now about nurturing care and gene expression. When a caregiver holds a baby and provides close loving contact, the baby’s senses are stimulated, and the baby is comforted and feels safe. The physical attention stimulates the baby’s brain development and affects the way genes are expressed. An emotionally nurturing environment is as important to physical development as good nutrition. To put it simply, nurturing can “turn on” genes for positive traits and suppress or “turn off” genes associated with negative outcomes.

Dr. Thomas Boyce, pediatrician and distinguished professor emeritus in the Departments of Pediatrics and Psychiatry at the University of California, explains nurturing environments are particularly important for children who are highly reactive or sensitive to context. He also refers to the animal research of both Dr. Steven Suomi and Dr. Michael Meaney, which is described below.

Next, Boyce explains that some children are particularly sensitive to their environmental situations. This highlights the importance of positive, nurturing environments.

What does animal research tell us about nurturing care?

Warwick (2005) explains that Michael Meaney’s work from McGill University on rodent models has given insight into how maternal care affects the response of young rats to stress. Mother rats lick their young and this is a possible equivalent to a human mother’s touch. Similar to humans, there are variations in parenting in rodents. Some mother rats lick their offspring more than others. Meaney has focused much of his research on comparing the offspring of high versus low-licking mothers. Meaney and his team have demonstrated that offspring of high-licking mothers release lower levels of stress hormones (glucocorticoids) when exposed to stress. Although the release of stress hormones is adaptive when confronted with a stressor, prolonged rises in glucocorticoids have deleterious effects, including deficits in learning and memory. Therefore, having a high-licking mother is advantageous, as these offspring have been shown to be less reactive to stress and demonstrate higher capacities for learning than those reared by low-licking mothers.

Dr. Stephen Suomi, chief of the Laboratory of Comparative Ethology at the National Institute of Child Health and Human Development in the United States, has done extensive research with rhesus monkeys. Suomi researches social competence and other behaviours in communities of rhesus monkeys, including attachment relationships and the impact of maternal nurturing on stress levels, aggression and eventual social status of their offspring. He is able to manipulate genetic and environmental factors. One example is to compare adult competence when an anxious baby monkey is raised by a nurturing foster mother rather than his own anxious mother (Suomi, 1999).

Animal studies allow scientists to study genetic expression. The following clip describes the primate laboratory at the National Institute of Health as well as two field sites that Suomi directs.

In the next clip, Suomi explains some of his findings with the genetically controlled groups of monkeys and the importance of mothering in influencing biology and behaviour. Suomi’s primate research demonstrates the genetic blueprint is actually shaped by the quality of nurturing care infant monkeys receive.

Nutrition and stimulation

Malnourishment and poor health make learning hard and often result in long-term cognitive deficits. Research around the world is demonstrating that early stimulation and good nutrition are both important contributors to healthy development. The late Dr. Fraser Mustard, founder of the Canadian Institute for Advanced Research, describes this research.

The following reading provides a short, clear summary of the evidence.

The Pakistan Early Child Development Scale Up (PEDS) Trial in Sindh, Pakistan evaluated whether the integration of early childhood psychosocial stimulation, alone or in combination with nutrition interventions, within a primary healthcare program had beneficial outcomes for children up to 24 months of age in terms of motor, cognitive, communication and social functions in rural Pakistan. The study included all children born in the geographical area along with the child’s primary caregiver, typically the mother.

The PEDS Trial evaluated the benefits of psychosocial stimulation interventions and the feasibility of scaling up an early childhood development (ECD) strategy within the primary healthcare system of Pakistan. Listen as Dr. Aisha Yousafzai, associate professor at the Harvard T.H. Chan School of Public Health, explains the background of the PEDS trial in which she was the principal investigator.

In the next clip, Yousafzai describes the research methodology of the study. Although final results of the study will become available in the near future, early trends indicated positive trends.

As Dr. Yousafzai describes, one of the groups of mothers in this study receive the ECD module plus the lady health worker services. In the next clip, listen as she and several others involved in the study, describe the ECD component of the sessions for mothers in this group and the benefits already observed. Helping mothers focus on their child’s development and observing milestones is considered an important component of this program.