Prenatal development and infancy - lecture 2

Question 1

conception

Answer 1

egg released, travels down folopian tube. Ovum
* 1/175th inch
* 1-2 released

Sperm
* 1/500th inch
* ~350,000,000 released
* ~500 reach the ovum

Question 2

stages of development

Answer 2

zygote
embryo
fetus (1st tri)
fetus (2nd tri)
fetus (3rd tri)

Question 3

zygote

Answer 3

weeks 1-2
One-celled zygote multiplies – blastocyst which burrows into uterus. Development of e.g., placenta & umbilical cord.

Question 4

embryo

Answer 4

weeks 3-8
length/weight 1/2-3cm / 5g
first development of core organs:
Primitive brain & spinal cord. Major internal
organs develop. External structures form

Question 5

fetus 1st tri

Answer 5

weeks 9-12
length/weight 8cm 30g
Nervous system, organs and muscles become organised and connected. Starts kicking, sucking thumb. Genitals formed

Question 6

fetus 2nd tri

Answer 6

weeks 13-24
length/weight 30cm/820g
All neurons present by 24 weeks. Eyes sensitive to light, reacts to sound

Question 7

fetus 3rd tri

Answer 7

weeks 25-38
50cm
3.5kg
Lungs begin to mature. Brain develops rapidly. Fat added under skin.

Question 8

influences on development

Answer 8

drugs–> Prescription & Illegal (Thalidomide; aspirin; heroine/crack)
smoking–>Low-birth weight & possible behavioural issues
alcohol–> Fetal Alcohol Syndrome, Interferes with cell duplication & migration, & deprives fetus of oxygen
Maternal illness–> poor nutrition; chronic stress

Question 9

how does premature birth and birth weight relate to chances of disability?

Answer 9

the lower the birth weight, the higher the chance of disability

Question 10

SLIDE 9 AND 10 NOT COMPLETED

Question 11

Motor development

Answer 11

piaget–>have to be able to move and explore and interact physically with the environment to have the best chance of cognitive development

Question 12

What is motor developmemt?

Answer 12

This development enables:
▪ Exploration of objects
▪ Exploration of surroundings
▪ Social interaction (e.g. pointing)
▪ This ability supports the development of:
▪ Social skills
▪ Cognition
▪ Language

Question 13

What are reflexes?

Answer 13

Reflexes are an innate automatic response to stimuli
▪ Reflex function reveals health of nervous system
▪ Some have survival value (e.g. rooting reflex)
▪ Others form basis of later motor skills (e.g.,stepping reflex)
▪ Most innate reflexes have disappeared after 6 months
▪ Some are permanent (e.g. eye blink)

Question 14

What are fine motor skills?

Answer 14

• Smaller movements
• Reaching, grasping etc

Question 15

What are gross motor skills?

Answer 15

• Also known as locomotor skills
• e.g. crawling, standing, walking

Question 16

What ages to specific motor skills develop?

1. (Grasps cube, Ulnar grasp)
2. sits alone
3. pincer grasp
4. walks alone
5. jumps

Answer 16

1. 3-4 months
2. 7 months
3. 9 months
4. 12 months
5. 2 years

Question 17

What is the Maturational Theory (Gessell 1940)?

Answer 17

▪ Cephalocaudal trend – head, arms/trunk, legs
▪ Proximodistal trend – head/trunk/arms then hands
and fingers

Question 18

What are cultural variations in prenatal development?

Answer 18

▪ Some communities promote behaviour where infants reach milestones earlier than US-centric model, or vice versa.
▪ WEIRD (Western, Educated, Industrialized, Rich, Democratic)

Question 19

What is perceptual development?

Answer 19

Five senses
▪ Touch
▪ Taste
▪ Smell
▪ Hearing
▪ Vision

Question 20

What are the perceptual skills of a newborn?

Answer 20

Touch
▪ Well developed, e.g. rooting reflex
Taste
▪ Can distinguish sweet, sour, bitter.
Smell preferences
▪ Like chocolate; don’t like rotten eggs!
▪ Survival function (identification of mother)
Hearing
▪ Prefer complex sounds
▪ Sensitive to speech sounds
Vision
▪ Least developed sense

Question 21

What is depth perception?

Answer 21

▪ Ability to judge distance between
objects and from self
▪ Necessary for reaching
▪ Survival function
▪ Visual Cliff (Gibson & Walk, 1960)
▪ Cues
▪ Kinetic (blink reflex at 3-4 weeks)
▪ Binocular (2-3 months)
▪ Pictorial (6-7 months)

Question 22

What is pattern perception?

Answer 22

▪ At birth, prefer patterned stimuli to plain
▪ With age, prefer more complex patterns - contrast sensitivity

Question 23

Memory development- How do we measure memory in pre-verbal
infants?

Answer 23

▪ Operant conditioning (e.g. Rovee-Collier,
1999)
▪ 3 months – remember for 1 week
▪ 6 months – remember for two weeks
▪ Memory highly context specific