What kind of memory shows the most growth during the middle and late childhood period?

Paediatr Child Health. 2012 Feb; 17(2): 81–83.

Language: English | French

Abstract

Middle childhood, from six to 12 years of age, is often known as the ‘forgotten years’ of development because most research is focused on early childhood development or adolescent growth. However, middle childhood is rich in potential for cognitive, social, emotional and physical advancements. During this period, the brain is actively undergoing synaptic pruning and, as such, is constantly becoming more refined, a process that is heavily dependent on a child’s environment. This discovery opens the door to optimizing the experiences a child needs to provide themselves with a strong foundation for adulthood. The present article reviews the neurological changes that occur in middle childhood, their impact on overall development and how to implement this knowledge to augment a child’s capabilities.

Keywords: Development, Neurobehavioural, Physical activity

Résumé

La période intermédiaire de l’enfance, de six à 12 ans, est souvent connue comme « les années oubliées » du développement, car une bonne partie de la recherche est axée sur le développement de la petite enfance ou la croissance à l’adolescence. Cependant, cette période est riche en potentiel sur le plan du progrès cognitif, social, affectif et physique. Le cerveau subit activement un élagage synaptique et devient donc de plus en plus raffiné, un processus qui dépend lourdement de l’environnement de l’enfant. Cette découverte ouvre la porte à l’optimisation des expériences que vit l’enfant afin d’établir des assises solides pour l’âge adulte. Le présent article aborde les changements neurologiques qui se produisent pendant la période intermédiaire de l’enfance, leurs répercussions sur le développement global et la mise en œuvre de ces connaissances pour accroître les capacités de l’enfant.

“What are you doing?” nine-year-old Emma asked me with wide-eyed curiosity for the second time in 10 min as I sat writing notes on the paediatric ward. Have you ever noticed how inquisitive school-age children are? The intricacies of their social interactions, the passion in their voice when they share a story, and the speed at which they learn and adapt is quite impressive. There are many changes that occur as they navigate the intricate path from preschooler to adolescent, changes that are integral to their overall development.

The “First Five Years of Life” campaign has made us all aware of the impact that early childhood has on a child’s future, yet it is equally essential to recognize that ages six to 12, often known as the middle childhood ‘forgotten’ years, are also a critical period that carries long-lasting influence. During this time, children’s brains are adapting rapidly. While they are becoming physically stronger and more coordinated, they are also becoming cognitively more abstract in their thought processes, and more aware of their own feelings and the world around them. It is a time rich in potential that is just waiting to be cultivated.

The role of the brain

From birth to young adulthood, the human brain is rapidly maturing, with the most rapid growth early on in life, when the brain is most plastic. Imaging and postmortem histology studies have shown that the brain undergoes selective pruning, a process in which some areas are enhanced, while others are selectively attenuated. This adaptive process is influenced, in many critical aspects, by daily experiences that can direct new axonal projections, and synaptic reductions and consolidations (1). Hence, despite any genetic predispositions for mental health or physical risk factors that a person may have, with proper nurturing and exposure to stimulating environments it is possible to alter one’s epigenetics and how one will perceive and interact with the world as an adult (2). This was best exemplified in a study by Pollak et al (3), who found that despite the early childhood experience of living in an orphanage, children who were placed in an enriched adoptive family began to perform better on physical, social and cognitive functions.

Based on Knudsen’s theory, middle childhood is considered to be a “sensitive period” because of the active role that experiences play in brain development (4). During middle childhood, the brain is in a constant state of flux: myelination is occurring within the corpus callosum and subcortical areas, which enables increased conduction speed and synaptic transmission between the right and left hemisphere, while at the sametime, the cortical gray matter is actively adapting. As this takes place, brain activity and behavioural responses advance. Across tasks, young children exhibit patterns of diffuse and widespread activation on functional magnetic resonance imaging while older children show more select regional activation. This is because synaptic pruning enables the brain to attenuate activity in certain areas, while maintaining or enhancing activity in other areas. Thus with age, fewer and more select regions of the brain are activated for specific tasks by responding selectively to the same stimuli (1). The degree to which this occurs is modulated by the experiences a child has. As such, children have a greater chance of reaching their potential when they have access and opportunity to engage in stimulating environments, experiences, and interactions that support and promote their individual capacities and capabilities (1).

Physical literacy

When you compare six and 12-year-olds as they throw a ball, you will notice that the younger child demonstrates significantly more extraneous movements, whereas the older child is more precise and purposeful (5). This is because through middle childhood, children develop increased physical abilities that parallel the process of synaptic pruning. This is why simply getting children moving during their elementary school years can improve their motor skills and initiate sustainable healthy living habits, while at the same time providing stimuli that augment synaptic remodelling. However, that is not all that activity provides. It has been found that physical activity through middle childhood plays an integral role in instilling self-confidence and in providing a conduit for learning.

Getting children in motion gives them a sense of accomplishment, resiliency and security. To them, they are just having fun, but physical activity places them in situations where they can have positive exchanges with their peers, while learning to be adaptable, creative, critical thinkers and effective communicators. Research has shown that the positive social and emotional stability afforded by physical activity is the best indictor of overall well-being and decreases the risk for mental health issues, while making children more resilient as they move into adolescence (1,6). A study involving 1300 children in 2001 by Browne et al (7), found a similar correlation. The study showed that recreational activities helped children with psychological disorders maintain social, physical and academic competences on par with children without disorders. The stability and friendships cultivated through activity acts as a protective factor for children at risk of behavioural and emotional problems (7).

The self-esteem gained from sport can also secondarily strengthen academic performance. However, this is not the only mechanism by which sport and academics are linked. Studies have shown that physical activity produces growth factors and proteins that protect and stimulate the brain, and improve memory, concentration and attention. This finding is supported by research from the University of Illinois (Illinois, USA) showing that fitter young children from the same socioeconomic backgrounds and with the same body mass index performed better on tests assessing attention and complex memory (8). Active children also have significantly larger basal ganglia and hippocampi, areas responsible for maintaining attention, coordination and memory (8,9). In Sweden, an analysis of 18-year-old boys in the army found that fitness correlated with higher IQs and satisfying careers, even among identical twins (10). This supports the belief that through aerobic exercise in middle childhood, one can contribute to the structure and function of the brain, thereby enhancing future neurocognition (11). The impact of physical education on brain development, intelligence and mental health, in addition to overall physical health, emphasizes the importance of encouraging physical literacy throughout middle childhood.

Cognitive and social development

Middle childhood is when children transition from dependent preschoolers to young individuals with an active role in their family and community structures. Their thoughts become more abstract, their behaviours and emotions more controlled and their decisions more independent (5). It is during middle childhood when neurons responsible for cognition, language and social skills are being consolidated.

From seven to 11 years of age, children gain cognitive control, with an increasing ability to respond selectively to stimuli and begin to process and understand material effectively. Feedback loops between the forebrain and midbrain transform, thus enabling flexible regulation of thoughts and actions in the presence of competing stimuli. Language control has a more prolonged maturation process, with gray matter maturation in the cortex of the temporal and frontal lobes stretching into adolescence (12). These rich periods of neuromaturation are the best time to expose children to an array of experiences which can strengthen the number and precision of these connections, and enhance their cognitive abilities and language capacity (13).

Socially, during middle childhood, children shift from an inward view of the world to an outward view. At seven years of age, children become more aware of their own feelings, realizing that they are distinct from others and, as such, they then begin to consider the feelings of others. The ability to do so requires a certain level of intelligence, communication, insight, empathy, altruism and morality. Morality is a progressive occurrence moving from an absolute sense of the rules to being able to analyze rules and judge what is right or wrong (1). Forming this prosocial behaviour of considering another’s point of view, with controlled emotion and empathetic insight, is dependent on genetics to a degree, but is largely dependent on parental guidance and modelling (14,15). It is at the same time, from six to 10 years of age, that children come to understand stereotypes (15). Thus, how one comes to view and interact with the world as adults is largely established during middle childhood.

Middle childhood: Where to begin?

The implications of neural plasticity, as they relate to moulding human development are far-reaching. They prove that the developmental process is initiated by genetics, but shaped by experience, making middle childhood a prime period to impact future change in a child’s life. The investments made during this period can yield favourable outcomes in the areas of future health, intelligence, social and emotional well-being. It is a self-perpetuating cycle, with each new experience modifying neural architecture, leading to the acquisition of new skills and abilities, that in turn, open doors to further opportunities. The key is to initiate the cycle by providing environments, structures and experiences that begin, and continue, to stimulate children’s minds and bodies to build a strong base for the remainder of their lives. Paediatricians can encourage families to begin this cycle with the following keys:

1. GET THEM MOVING: With even a small amount of aerobic activity, children can improve their IQ, as well as their psychological and physical health. Governments and school boards must recognize the significance of physical literacy, and families can start by taking small steps toward overcoming a sedentary lifestyle.

2. STRETCH THEIR MINDS: Get children engaged in learning. With access to recreation, leisure, arts and cultural activities, children will develop competencies, interests, social skills, and positive peer relationships that improve their overall well-being and practical abilities.

3. EMPOWER THEM WITH SELF-CONFIDENCE: Children have a natural determination to excel and be socially involved. By encouraging them to participate in programs and activities that promote positive peer interactions and proficiencies, children will gain a sense of accomplishment and thus, self-confidence.

Although families are the most direct source of influence in a child’s development, communities and governments also play a pivotal role because they determine many of the resources and infrastructures available to the public. Hence, close collaboration of parents, teachers and physicians is essential for giving children a sense of competency in the world, and within themselves, while laying the foundation for the developmental work in the years ahead. With such considerable potential for advancement, middle childhood is the optimal time to foster talents and interests. Ultimately, it is a time well worth investing in for all involved in a child’s life.

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