Transcript 023_W2002_Development

Three Minute Review
NONVERBAL COMMUNICATION
• eye contact
• body language
• gestures
– why do people gesture on the phone?
• interactional synchrony
• deception
LANGUAGE DEVELOPMENT
• Skinner vs. Chomsky
– operant conditioning vs. language instinct
• children’s overgeneralization
– grammatical errors and “Wug test”
LANGUAGE DEVELOPMENT
• critical periods
– ~6 months for learning phonemes
– ~6 years for learning grammar
• language learning in animals
– lower larynx enables human speech
– apes have to use ASL or symbolic language
– debate about whether it’s really “language”
Test Yourself
•
A.
B.
C.
D.
E.
A child who uses the word “wawa” to refer
not only to water but to milk, juice and other
drinks is:
overextending the word
underextending the word
demonstrating conditioning of the word
“wawa” with any liquid
babbling
autistic
Development
• Physical Development
• Cognitive Development
• Social Development
Brain Development
Brain Development
• during pregnancy, the brain
can be highly susceptible to
teratogens
– radiation, drugs, viruses, toxins
– explanation for morning
sickness?
• fetal alcohol syndrome
– cluster of defects occurring in
infants born to mothers that
drink heavily during pregnancy
– leading cause of mental
retardation
– even moderate drinking (e.g.,
three beers a day) may lead to
children with a lower IQ and
shorter attention span
Neural Development
• Grow, then prune
• Neural Darwinism
– make too many neurons, then prune the ones you’re not using
– “use it or lose it”
– there are 30-60% more neurons in the fetus than in the adult brain
Myelinization
• basic sensory and motor areas become
myelinated early
• association areas become myelinated later
Cognitive Development
The infant’s world is a “blooming, buzzing confusion”
• -- William James
• How can you study perception and cognition in a
non-verbal being (preverbal child, animal)?
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–
–
–
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Visual tracking
Preferential looking
Eye movement monitoring
Habituation
Sucking
Visual Tracking
• newborns will track facelike stimuli
• innate preference for faces?
Orienting and Habituation
• Orienting reflex
– humans, including infants, pay more attention to
novel than familiar stimuli
• Habituation
– infants get bored with repeated presentations of
the same thing
• Habituation paradigm
– repeat the same stimulus over and over again,
then change it slightly
– does infant spend more time looking at new
stimulus?
Preferential Looking
•
•
present two stimuli on either side of centre
watch where infants look
– in the best studies, the mom and experimenter are blind to the stimuli
•
spontaneous looking preferences
– e.g., infants prefer high contrast
•
habituation
– familiarize infant with one stimulus, then present it in combination with a new
stimulus
– infant looks more at new stimulus  infant could tell the difference
– infant looks equally at old and new stimuli  infant couldn’t tell the difference
What have we learned?
• Although newborns can see faces, faces
must appear very blurry to them
Eye Movements
• newborns look at outside features of faces
• older infants, like adults, spend much time
looking at eyes and mouth
Behavior
• Visual Cliff
– Will the baby crawl over the glass to get to mom?
• mobile infants won’t
• pre-mobile infants did not appear bothered when placed
on the glass
Sucking Response
• newborns suck more when they hear their
native language
• newborns suck more when they hear their
mom’s voice
Critical
Periods
(See Gray, pp. 135)
Konrad Lorenz
1903-1989
Critical period: A period in development
during which some event has a longlasting influence on the brain and
behavior that it would not have if it
occurred outside that period
Imprinting
• baby ducks and goslings
will follow on the first
individual they encounter,
even if it’s a human rather
than the mother
• imprinting must happen
within five days after
hatching
Does Development Occur
Continuously or in Stages?
Jean Piaget
Jean Piaget
1896-1980
• Piaget, a Swiss
psychologist, believed
that “children are active
thinkers, constantly trying
to construct more
advanced
understandings of the
world”
• These “understandings”
are in the form of
structures he called
schemes
Assimilation and Accomodation
• Schemes are frameworks that develop to
help organize knowledge
• Assimilation - process of taking new
information or a new experience and fitting it
into an already existing scheme
• Accommodation - process by which existing
schemes are changed or new schemes are
created in order to fit new information
Piaget’s Approach
• Primary method was to ask children to solve
problems and to question them about the
reasoning behind their solutions
• Discovered that children think in radically
different ways than adults
• Proposed that development occurs as a
series of ‘stages’ differing in how the world is
understood
Sensorimotor Stage
birth - 2 years
• Information is gained through the senses and motor actions (looking,
touching, mouthing)
• In this stage child perceives and manipulates but does not reason
• Infant gradually becomes aware of relationship between own actions
and their effects on environment
• Object permanence is acquired
Sensorimotor Development
Object Permanence
• 8 - 10 mos.: Infant begins to
understand that objects exist
even when not in view
Preoperational Stage
2 - 7 years
What does the doll see?
• Represents things with
words and images but
lacks logical reasoning
• Can think symbolically
(e.g., pretending a stick is
a gun)
• Thinking is egocentric: has
difficulty taking the
viewpoint of others
• Fails to understand
conservation
Conservation of Number
Is there the
same number
in each row?
Conservation of Length
Which stick is
longer?
Conservation of Volume
Which
container has
the most
volume
Conservation of Mass
Which is bigger?
Concrete Operational Stage
7-12 years
• Can think logically about
objects and events
• Can see other’s
perspective
• Achieves conservation of
number (~age 6), mass
(~age 7) and weight (~age
9)
Formal Operational Stage
11 years and up
• Can think logically about
abstract propositions and test
hypotheses systematically
• Can understand hypothetical
propositions
– e.g., If all animals can fly and if
rhinoceroses are animals, then all
rhinoceroses can fly.
• Becomes concerned with the
the future and ideological
problems
• Not achieved by all adults
Critiques of Piagetian Theory
•
•
•
•
Underestimates children’s abilities
Overestimates age differences in thinking
Vagueness about the process of change
Underestimates the role of the social
environment
– tests were done on Western European kids
– Vygotsky argued culture and social interaction
were critical to development
• Lack of evidence for qualitatively different
stages
• Not well integrated with neuroscience
Contradictory Experiments
• In preferential looking
experiments, 4 month
old infants who did not
demonstrate object
permanence
nonetheless looked
longer at an
unexpected occlusion
event
• Preoperational children
chose the column with
more M&Ms
Information Processing Perspective
• Focuses on the mind as a system, analogous
to a computer, for analyzing information from
the environment
• Developmental improvements reflect
–
–
–
–
increased capacity of working memory
faster speed of processing
new algorithms (methods)
more stored knowledge