Week 2

Question 1

Timing and sensitive periods for fatal development

Answer 1

*look up image

Question 2

Effects of environment - poverty

Answer 2

Associated with:
– Increased stress
– Fewer but more hostile interactions 
– External environmental risks
– Serious developmental risks

Question 3

Teratogens

Answer 3

• harmful environmental agents/conditions that impair prenatal development and lead to death, birth defects, or later emotional, behavioural, and/or intellectual impairments
• Usually these abnormalities arise in the third to eighth weeks of pregnancy, when the major organ systems are forming

Question 4

Examples of teratogens

Answer 4

• Prescription drugs: thalidomide, accutane (Vitamin A)
  Illegal drugs: marijuana, cocaine alcohol and tobacco
  (Pre-natal exposure to smoking alters gene expression, linked to ADHD)
• Environmental hazards: X-rays, pollution, disease: Rubella, HIV/AIDS, STDs
• Parental factors: maternal malnutrition, stress, age; paternal age, Vitamin C deficiency, exposure to toxins, smoking

Question 5

Teratogen risk factors

Answer 5

Dose
Heredity
Interaction effects
Timing sensitive and critical periods
Environmental interactions

Question 6

Teratogen risk factor - dose

Answer 6

Generally larger dose over
longer time → more damage May be safe thresholds.
-> However, example: alcohol

• WHO recommends no known safe level of alcohol during pregnancy
• Australian NHMRC Guidelines- safest = no alcohol during pregnancy or breastfeeding

Question 7

Teratogen risk factor - heredity

Answer 7

e.g., alcohol

dehydrogenase gene

Question 8

Teratogen risk factor - interaction effects

Answer 8

e.g., alcohol + marijuana, no safe thresholds

Question 9

Teratogen risk factor - timing sensitive and critical periods

Answer 9

*look up image

Question 10

Teratogen risk factor - environmental interactions

Answer 10

e.g. low SES, smoking, & developmental delays (Perera et al., 2006)

Question 11

Fetal alcohol spectrum disorders

Answer 11

Result from exposure to alcohol (again a teratogen)
• 1 – 3 per day: ARND (Alcohol-related Neurodevelopmental Disorder) or Fetal Alcohol Effects
• > 3 per day or binging (5+) in early pregnancy: Fetal Alcohol Syndrome

Question 12

Expressions of FAS depend on

Answer 12

– Timing of alcohol consumption relative to the stage of fetal development
• Incl. exposure prior to pregnancy, incl. by father
• Most vulnerable between 3 – 6 weeks
– Dose and frequency of consumption
– Socio-behavioural risk factors (maternal age/duration of drinking, low SES, race, genetic differences, polydrug use)

Question 13

Infant brain development

Answer 13

• At birth
– birth: 25% adult brain weight

• 2 years: 80%
– Increases due to dendrite growth and myelination
5 fold increase in dendritic density by 2 years (Diamond, 1990)

Question 14

Determinants of brain development

Answer 14

Maturation + Stimulation 
• Deprivation studies
e.g., Rozenweig’s (1984) rat experiments
e.g. Human deprivation studies (Beckett et al., 2006) 
*look up image - Beckett 2006

Question 15

Depth perception

Answer 15

Ability to judge distance of objects
• Tied to motor development, esp. crawling
–the Visual Cliff

Question 16

Toddler imitation

Answer 16

• Depends on motor and cognitive skills necessary to carry out the action to be imitated.
• @ 15 months, children this age are usually mobile and have some hand- eye coordination.
• “Serve and return” (video, Kingston & his dad)