The Process of Development John Sargent, MD

Objectives of this lecture – to learn 1.) Framework for understanding development 2.) Skill progressions through developmental process 3.) Aspects of family and community that promote development

Neurobiology of development Neural tissues begin development and differentiation at 2 weeks gestation By 8 weeks cells begin to divide into cortical and subcortical neurons Between 12 and 20 weeks neurons migrate toward cortical destination

The next step is connections among neurons occurring throughout central nervous system These connections are refined to organize cortical circuits and subcortical structures (24 to 28 weeks gestation)

Number of neurons in humans peaks at 28 weeks gestation (40% more than in adult)

Further processes occurring during fetal life include dendritic growth, synaptogenesis and myelinization

Rapid growth and differentiation of central nervous system tissues underlies the vulnerability to toxins, drugs and alcohol and nutritional status during fetal growth

Continued maturation of central nervous system tissue includes both myelinization and synaptic pruning which continues from childhood through adolescence

Gray matter formation follows an “inverted U-shaped curve” with peaks occurring between 12 and 16 years of age

Gray matter areas that organize sensorimotor activity mature first

Higher order association areas that govern language and memory mature later in preschool period

Frontal and prefrontal cortex continue maturing through adolescence into young adulthood reflecting maturation in judgment, values, planning and impulse control

Developing brain structures support developing reading and language skills, with interference with brain development leading to dyslexia

Development of “inhibitory control” – the capacity to control behaviors that conflict with personal and societal norms also occurs with age into young adulthood

This capacity is at the heart of cognitive and emotional maturation, including the ability to suppress automatic responses in favor of less automatic responses

This capacity relies upon activation of prefrontal cortices as well as thinning of cortex and continuing myelination of frontostriatal fibers

The capacity to read social and emotional cues, including facial cues depends upon the developing capacity of prefrontal cortex to modulate limbic activity which occurs during adolescence

Pruning of synaptic connections occurs in unused connections

Mirror neurons and biobehavioral reactivity have a great deal to do with the development of empathy Mirror neurons and biobehavioral reactivity have a great deal to do with the development of empathy

Cognitive processing improvement is also related to enhanced myelination increasing the speed of neuronal transmission and communication developed through childhood

During infancy the infant’s capacities – smell, suck, grasp, capacity to be comforted reinforce maternal investment and care

Further infant abilities – gaze, smile, nuanced cry, social engagement, snuggle, pleasure upon satiation further reinforce parental engagement

The influence of post partum depression, chaotic home life, domestic violence, parental substance abuse can be significant especially in early childhood

Attachment relationship between child and caretaker also significantly promotes and regulates development

Secure attachment is a description of a relationship that the child trusts to bring hurt and emotional distress to, trusting that the adult will assist with calming and regulation

In a secure attachment relationship the child is upset, the parent becomes upset, calms herself and the child calms in response

2 types of insecure attachment relationships have been described – avoidant and resistant

Avoidant children suppress emotion while resistant children persist in being upset

In situations of abuse children do not develop a unified strategy for regulating disruption and behave in an erratic and dysregulated fashion

Secure attachment leads to more social capacity, successful regulation of emotional upset, improved peer relationships and improved behavior regulation in school

Parental connections also lead to optimal cognitive development in first 2 years of life

Neural plasticity facilitates recovery from early maltreatment, parental loss and early adversity of other types

Plasticity is facilitated by consistency, availability of support and coherent family narratives

Competency, novelty and praise drive development

Capacity to do things and consistent availability of parental support assist navigation of insecurity associated with new challenges

Development leads to new skills – language, peer relationships, learning and following rules, gaining success in school and on playground

Parental availability and responsiveness play significant roles in reinforcement of children’s developing skills

Important aspects of the community that support development include A.) Pediatric care, child mental health care B.) Access to safe and supportive child care and preschool C.) Early childhood intervention to support maximal development D.) Home visiting, supportive neighborhoods

E.) Adequate effective schools with committed engaged teachers F.) After school opportunities G.) Engaging spiritual communities

H.) Safe neighborhoods, meeting places & playgrounds I.) Coaches, leaders and programs to build and develop individual talents J.) Groups (like 4-A, scouts) which support group participation and group success

Be aware of the role of temperament and intrinsic capacities in engaging in family and community supports Development is based on genetic endowment influenced by environmental circumstances