Developmental
Issues, Prenatal
Development, and the
Newborn
Module 7
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D evelopmental Issues, Prenatal
D evelopment, and the N ew born
Prenatal Development and
the Newborn
 Two Major Developmental Issues
 Conception and Prenatal
Development
 The Competent Newborn
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Prenatal Development and the
Newborn
BIG QUESTION: How, over time, did we come
to be who we are? From zygote to birth,
development progresses in an orderly, though
fragile, sequence.
People used to think that babies began life as a
“blank slate” with an empty brain and no
abilities. We now know that they are born with
innate abilities.
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Conception
A single sperm cell (male) penetrates the outer
coating of the egg (female) and fuses to form
one fertilized cell.
Lennart Nilsson/ Albert Bonniers Publishing Company
Lennart Nilsson/ Albert Bonniers Publishing Company
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Prenatal Development
Prenatal Period: the 9 months b/w conception and
birth. A zygote is a fertilized egg with 100 cells that
become increasingly diverse. At about 14 days the
zygote turns into an embryo (a and b).
Biophoto Associates/ Photo Researchers, Inc.
Lennart Nilsson/ Albert Bonniers Publishing Company
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Embryonic Stage
• During this stage-the genetic plan
determines how all the organs will begin to
form.
• Differentiation: embryo’s cells begin to
specialize.
• Before differentiation, embryonic stem cells
are capable of forming into any organs of
the body.
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Prenatal Development
At 9 weeks, an embryo turns into a fetus (c and d).
Teratogens are chemicals or viruses that can enter
the placenta and harm the developing fetus.
Lennart Nilsson/ Albert Bonniers Publishing Company
Lennart Nilsson/ Albert Bonniers Publishing Company
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Prenatal Development of the
Brain
• Brain grows new neurons at 250,000 per minute.
• By birth, it has produced 100 billion.
• As the new brain cells are produced, they actually
migrate out of the neural tube and then extend
their axons and dendrites to make connections
with other newly formed neurons.
• **How they do this is part of ongoing research.
• *the basic plan for wiring the brain—must be
contained in the genetic code.
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Teratogens: Prenatal
Toxins
• Although the placenta screens out some
potentially dangerous substances, many can
pass through-including viruses like HIV,
certain drugs, and other chemicals-heroin,
nicotine, alcohol.
• Fetal Alcohol Syndrome (FAS)-symptoms
can include mental retardation, poor motor
coordination, impaired attention, and
hyperactivity.
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The Competent Newborn
Neonatal Period
Infants are born with
reflexes that aid in
survival, including
rooting reflex which
helps them locate food.
Ex. Rooting, grasping,
postural reflex
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Habituation
• Defined: a decrease in responding with
repeated stimulation.
• A novel stimulus gets attention when first
presented but the more often its presented,
the weaker the response becomes.
• This seeming boredom with familiar stimuli
gives us a way to ask infants what they see
and remember.
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Recovery
• Following Habituation to one stimulus, the
tendency for a second stimulus to arouse
new interest—often used to test whether
infants can discriminate between stimuli.
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Novelty Preference
Procedure
• Used it to ask 4 month olds how they
recognize cats and dogs.
• 1. first showed pictures of cats and dogs
• 2. Found that after looking at a series of
cats or a series of dogs, they looked at
hybrid.
• Shows that they focus on face first-not
body.
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The Competent Newborn –
Neonatal Period
Offspring cries are important signals for parents to
provide nourishment. In animals and humans such
cries are quickly attended to and relieved. why?
Because it’s a behavior parents are predisposed to find
highly unpleasant and very rewarding to relieve.
Lightscapes, Inc. Corbis
Carl and Ann Purcell/ Corbis
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