Neurological and cognitive development from infancy through childhood

Developmental Timeline

The development of an individual is the result of maturation of the nervous system and psychological reactions, which in turn is determined through genetics and environmental factors. The study of an individual and his environment is summarized under the biopsychosocial model. A better understanding of human psychological, cognitive and moral development is largely dedicated to the efforts of Erik Erikson, Jean Piaget, and Lawrence Kohlberg.

Brain and Nervous System Development

Neurologic development begins in the third week of intrauterine life, marked by the development of a neural plate on the ectodermal surface. In folding of this plate produces a neural tube, which is destined to be the future Central Nervous System, and a neural crest, which forms the peripheral nervous system. Neuroectodermal cells differentiate into neurons. The forebrain, midbrain and hindbrain are evident by the fifth week, during which, the dorsal and ventral horns of the spinal cord have also begun to form, along with their motor and sensory nerves. Myelination of these nerves begins by mid-gestation and continues up to the second year of life. (Kliegman, Behrman, Jenson & Stanton, 2009)

Axons and dendrites develop most rapidly during the first trimester. DNA replication, which is a marker of brain growth, is greatest before mid-gestation and in the first few months of life. By the fortieth week of gestation, the structure of brain development is complete. Synapses are pruned back considerably and new connections continue to form after birth. (Kliegman et al., 2009)

Cognitive and Moral Development

Piaget's theory of development divides the lifespan of an individual into four stages: sensorimotor, preoperational, concrete operational and formal operational. The first stage of development lasts from birth to two years of life, and is known as the sensor motor stage. At this stage, children learn through active interaction, through their five senses, with their surroundings. They learn to crawl, walk, point and grasp during these two years. As an infant grows, it progresses to the next few stages of development, which is characterized by higher language and mental capabilities. Eventually, a child develops the reasoning skills, which is the most complex level of cognitive development. (Rathus, 2010)

Kohlberg's theory tries to expand the theory of morality mentioned briefly in Piaget's theory. This theory organizes six stages, each under three different levels. The first level of pre-conventional morality reflects an individual's ability to reason an action, which is either to avoid punishment or is based on an individual's needs. The next level is conventional morality, at which stage children are no longer impressed by a single authority and are able to see that there are two sides to a given issue. The final level is post conventional morality, at which point individuals are more concerned with principles and values for a society's sake. (Rathus, 2010)

Erikson approach to development focused on the battle between negative and positive attitudes that an individual may develop. These include: trust and. Mistrust; autonomy, shame and doubt; initiative and guilt; industry and inferiority; identity, role confusion, intimacy and isolation; generativity and absorption; and lastly integrity and despair. Each stage emerges gradually as an infant moves into adulthood and up to the level of a senior citizen. (Rathus, 2010)