Maturation, Growth, and Brain Development

Neonatal period (0-1 months)

• born with reflexes - behavioural patterns in response to specific stimuli

• reflexes include: rooting, sucking, swallowing, stepping, babinski, grasping, and moro

• bones are soft and pliable, will harden and fuse over time

• will have all muscle fibres needed

Development of height and weight

• 0-2 yrs: rapid growth; at 2 yrs, children are half of their adult height and 4x their birth weight

• 2 yrs - puberty: gain 2-3in in height and 6-7 pounds each year

• puberty: experience 2-3 yr growth spurt - 2-4 inches and 10-15 pounds a year

Brain development key ideas

• most developed areas are lower brain centres - consciousness, reflex, vital functions

• first 6 monthsL primary motor and sensory areas develop

• brain growth spurt: 7th prenatal month-2 years = more than half of brain weight gain

• brain continues to mature; myelinization and cerebral lateralisation

Brain growth spurt

• majority of neurons are formed by the second trimester

• brain growth attributed to development of glia, which nourish the neurons and facilitate myelinization

• formation of synaptic connections in different brain sites

Myelinization

• neurons enclosed in myelin sheaths; facilitates impulse transmissions

• infants have well-insulated paths between sense organs and brain

• myelinization of paths between brain and muscles leads to motor development in infancy and childhood

• continues across childhood and adolescence - reticular formation and frontal cortex not fully myelinated at puberty; this explains why adolescents have better attention spans

Synaptic pruning

• born with more neurons than needed, and ones that are not being used lose synapses but are still there in case of emergency

• due to this, infant brains are highly plastic - can learn a lot and bounce back

Cerebral lateralisation

specialisation of brain functions in left and right cerebral hemispheres - some laterality in newborns, but increases across development

Visual and perceptual development

• newborns seek visual stimuli, which leads to the paths becoming myelinated

• 2-3 months maturation: see more detail, construct visual forms

• development of form perception requires continous play and interaction with the environment

• depth perception develops around 3 months (visual cliff experiment)