• Heritability

A statistical estimate of the proportion of the measured variance

on a given trait among individuals in a given population

that is attributable to genetic differences among the individuals

• Important restrictions:

• Heritability estimates apply only to: populations, not individuals
• Heritability applies only to a particular group living in a particular environment at a particular time
• High heritability does not: imply immutability
• Heritability estimates tell us nothing about:differences between groups

Brain Development


 

• Neurogenesis --

• Myelination

• Synaptogenesis

• Synapse Elimination

Experience and The Brain (see textbook for definitions)

• Plasticity

Experience-expectant plasticity

Sensitive periods

Experience-dependent plasticity
 
• Plasticity, Brain Damage, and Recovery

“Worst time” is:
 

“Best time” is:
 

• Sleep

• Nutrients


Breast milk is the ideal food for an infant; Recommended that babies are breast fed for the first 12 months
 

• Stimulation


Synaptic pruning is taking place; specific connections are made and others are lost without stimulation
 

• Avoid trauma

Trauma elevates stress hormones (cortisol) that can damage the brain

What kind of stimulation is important for early brain development?
 

Remember the video -- babies need to be held, touched, talked to, sung to, consoled when crying, interesting things to look at (people), toys to explore and manipulate

They don't need flash cards, videos, etc.

Depends on nature and nurture, genetics, and the environment

See textbook:

Nutritional Behavior
Breast feeding
Food preference
Eating disorders

Undernutrition
 

• Marasmus: prolonged insufficient calories

Results from starvation
Sufferers are extremely thin and shriveled
Muscles, even heart muscles, waste away as muscle protein is used up
 
• Kwashiorkor: prolonged insufficient protein

Prevalent after weaning when child is switched to starchy low protein diet
symptoms:
• puffy skin
• swollen belly
• reddish cast to hair
• dermatitis and listlessness

• Treatment for Marasmus and Kwashiorkor
• Symptoms can be reversed if treated in time
• Mild mental retardation and stunted growth may be permanent

• Incidence
• less than 1% of developing countries
• more common in Asia than Africa

Other forms of Undernutrition

    More common forms of malnutrition -- affect large numbers of children world-wide, also in the US

• Protein-energy malnutrition: less than recommended amounts of protein and/or calories

• Mineral and iron deficiencies: less than recommended amounts of minerals and iron
• Can result in iron-deficiency anemia


Long-term effects of protein-energy malnutrition

• lower IQ scores
• poor health
• poor school performance
• reduced brain size


How does malnutrition affect brain and cognitive development? (see also Figure 3.14 in text)

• Directly
 reduces size of brain
• Indirectly
 affects physical and motor development
 children explore less, learn less

Effects of nutritional supplements

    Nutritional supplements are important in treating malnutrition. But they are more beneficial when:

• started early, e.g. in pregnancy
• combined with improvements in heath care
• combined with stimulation and parent education
• interventions that affect the environment as well as the individual child

Causes of Malnutrition

Immediate:

inadequate food consumption

desease/illness

• Underlying
• Not enough food in the home
• Inadequate health care for women and children
• Poor health services and sanitation

• Basic
• Poverty
• Political, economic, and cultural factors


To treat malnutrition, we need to address the basic and underlying causes (e.g. poverty) as well as the immediate ones

Review of Major Themes:

• Nature and Nurture

• The Active Child

• Continuity/Discontinuity

• The Sociocultural Context

• Individual Differences

• Research and Children’s Welfare