Prenatal development and infancy - lecture 2 Flashcards
what is conception
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
stages of development
zygote
embryo
fetus (1st tri)
fetus (2nd tri)
fetus (3rd tri)
zygote
weeks 1-2 of conception
One-celled zygote multiplies – blastocyst which burrows into uterus. Development of e.g., placenta & umbilical cord.
embryo
0weeks 3-8
length/weight 0.5-3cm / 5g
first development of core organs:
Primitive brain & spinal cord. Major internal
organs develop. External structures form
fetus 1st tri
weeks 9-12
length/weight 8cm 30g
Nervous system, organs and muscles become organised and connected. Starts kicking, sucking thumb. Genitals formed
fetus 2nd tri
weeks 13-24
length/weight 30cm/820g
All neurons present by 24 weeks. Eyes sensitive to light, reacts to sound
fetus 3rd tri
weeks 25-38
50cm
3.5kg
Lungs begin to mature. Brain develops rapidly. Fat added under skin.
influences on development
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
AFFECTS CNS THE MOST
how does premature birth and birth weight relate to chances of disability?
the lower the birth weight, the higher the chance of disability
SLIDE 9 AND 10 NOT COMPLETED
what is Motor development
piaget–>have to be able to move and explore and interact physically with the environment to have the best chance of cognitive development
What is motor developmemt?
This development enables:
▪ Exploration of objects
▪ Exploration of surroundings
▪ Social interaction (e.g. pointing)
▪ This ability supports the development of:
▪ Social skills
▪ Cognition
▪ Language
What are reflexes?
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)
What are fine motor skills?
- Smaller movements
- Reaching, grasping etc
What are gross motor skills?
- Also known as locomotor skills
- e.g. crawling, standing, walking
What ages to specific motor skills develop?
- (Grasps cube, Ulnar grasp)
- sits alone
- pincer grasp
- walks alone
- jumps
- 3-4 months
- 7 months
- 9 months
- 12 months
- 2 years
What is the Maturational Theory (Gessell 1940)?
▪ Cephalocaudal trend – head, arms/trunk, legs
▪ Proximodistal trend – head/trunk/arms then hands
and fingers
What are cultural variations in prenatal development?
▪ Some communities promote behaviour where infants reach milestones earlier than US-centric model, or vice versa.
▪ WEIRD (Western, Educated, Industrialized, Rich, Democratic)
What is perceptual development?
Five senses
▪ Touch
▪ Taste
▪ Smell
▪ Hearing
▪ Vision
What are the perceptual skills of a newborn?
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
What is depth perception?
▪ 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)
What is pattern perception?
▪ At birth, prefer patterned stimuli to plain
▪ With age, prefer more complex patterns - contrast sensitivity
Memory development- How do we measure memory in pre-verbal
infants?
▪ Operant conditioning (e.g. Rovee-Collier,
1999)
▪ 3 months – remember for 1 week
▪ 6 months – remember for two weeks
▪ Memory highly context specific
