Infancy
Chapter 4-6
Psyc311
Dr. Jen Wright
infant brain
one of the last organs to develop…
difference between species
• Humans do not have the
Species
largest brain – but they
Human
have the largest EQ.
Dolphin
• Encephalization EQ+IQ
Chimpanzee
Quotient (EQ)
– Average brain mass/body
weights for a species.
– Average for
species/average
mammalian value.
EQ
Species
EQ
7.4 Cat
1.0
5.3 Horse
0.9
2.5 Sheep
0.8
Rhesus
Monkey
2.1 Mouse
0.5
Elephant
1.9 Rat
0.4
Whale
1.8 Rabbit
0.4
Dog
1.2
2.5
Parrot
brain development
• Most brain development
happens outside (instead of
inside) the womb
– Monkey newborn 70% adult size
– Human newborn 25% adult size
• Most growth occurs in first 3
yrs
– 3 yrs old 80% adult size
– 5 yrs old 90% adult size
developmental processes
• Neurogenesis – proliferation of neurons
through cell division
– 250,000 cells “born” every minute
• Synaptognesis – formation of
connections
– Each neuron forms 1000’s of connections
– Axons elongate towards specific targets
– Dendritic “trees” increases in size and
complexity
– By 6 months 2 x more synaptic connections
developmental processes
developmental processes
• Synaptic pruning – elimination of
excess synapses
– Streamlines neural processing
– Without synaptic pruning, children
wouldn't be able to walk, talk, or even
see properly.
• Myelination – insulating sheath
– Happens at different rates into
adolescence
– Certain areas are myelinated first
patterns of brain growth
importance of experience
• Plasticity – brain’s ability to change w/ experience
• Experience-expectant plasticity (experiences present
throughout evolution)
– Economizes on material encoded in genes
– Development will occur within a normal range of
environments
Examples?
– Level of vulnerability in timing • vision
• Sensitive periods
• language
announcements
• Psychology Club Event
– Volunteering in the Community
– 9/29 (next Weds) 5:15pm, ECTR 116
• Feedback for in-class debate
• Group write-ups – pick up after class.
• Study session for Exam 01
– 9/29 (next Weds) 7:00pm, ECTR 113
– 35 MC/TF questions (2pts each)
– 2 essay q’s (20 pts + 10 pts) – I will give you potential
q’s in advance
production
comprehension
both languages
2nd language
native language
importance of experience
• Experience-dependent plasticity
(experiences of individual)
– Brain sculpted by idiosyncratic experiences
– Responsive to richness of environmental
stimuli
– Important in development of expertise
• More brain resources dedicated to processing
• E.g. musicians’ cortical representation of hands
effect of deprivation
effect of deprivation
importance of sleep
• Regular and ample sleep correlates with normal
brain maturation, learning, emotional regulation,
and psychological adjustment in school and
within the family.
importance of sleep
importance of sleep
• REM sleep – critical for neural development
in brain, esp. for activity-dependent
development
– E.g. visual system
– Facilitates learning/memory
• Sleep deprivation linked with later problems
– E.g. ADHD, learning disabilities
• Babies most at risk of disruption
– Premature infants in IC units
stress and brain development
• Exposure to excessive stress hormones is bad for brain
development.
• Early symptoms of PTSD
• The brain can become incapable of producing normal
stress responses.
– Hyper-vigilance (Ghosts in the Nursery)
– Emotional flatness
• Physical/emotional abuse and neglect can be equally
damaging.
what is attachment?
attachment theory
• Attachment refers to the close,
emotional bond between an infant and
his/her primary caregiver.
• Psychoanalytic Theory (Freud)
– Driven by oral needs during the first year
– Emphasized early experiences on later
outcomes
• Behaviorist Perspective (Skinner)
– Driven by the need for food
– Learns to associate contact with mother
with food
– Mother’s closeness continually reinforced
attachment theory
• Ethology (Lorenz)
– Rooted in Darwin’s Evolutionary
Theory
– Focused on the adaptive value of
behavior
– Bond necessary for survival
– Imprinting
primary criticisms
• Love (i.e., attachment) seen as secondary to
instinctive or survival needs
• Harlow believed that the need for love and
affection was necessary for survival
announcments
•
•
•
•
•
Psyc Club – Volunteering in the Community
Exam study session
Weds, 7-9pm, ECTR113
Friday – Ch 4-6 Ask yourself Q’s due
How do you want to spend Friday?
– A) lecture
– B) ask yourself q’s and study guide!
• Exam 01- Monday!
Harlow’s monkeys (1958)
• Early work with monkeys
• Cloth & wire mother
– Only one equipped with feeding
apparatus
– Monkeys randomly assigned
– Observed for 5 months
• Both groups preferred cloth mother
24
Mean
hours
per
day
18
.
.
.
.
. .
.
12
.
.
6
0
Infant monkey fed on
cloth mother
Infant monkey fed on
wire mother
Hours per day spent
with cloth mother
Contact Time with
Wire and Cloth
Surrogate Mothers
.
.. . .. .. . Hours
per day spent with
wire mother
.
.
1-5
11-15
21-25
6-10
16-20
Age (in days)
Harlow’s monkeys (1958)
• http://www.youtube.com/watch?v=hsA5Sec6dAI
• http://www.youtube.com/watch?v=caM4f6ZZBE&feature=related
attachment theory
• John Bowlby
– Observations of children in
institutionalized care
• Infant has built-in behaviors to keep
parent close
• Gives way to true affectionate bond
• Serves 2 purposes
– Secure base
– Internal working model
attachment theory
• Mary Ainsworth (1979)
– Developed Strange Situation
– Work revealed 4 types of attachment behavior
•
•
•
•
Securely Attached
Insecure Avoidant
Insecure Resistant
Insecure Disorganized
• http://www.youtube.com/watch?v=QTsewNrHUHU
internal working model
cultural variation
social learning
facial recognition
mirror neurons
• Found in the frontal and parietal lobes
• Fire when you
– You engage in an activity (reaching out one’s
hand)
– You observe someone else engaging in the
same activity.
• Fire more strongly when action has
some purpose or content
– reaching out one’s hand for a cup.
• MN’s play a clear role in
learning/imitation.
• May also play a role in “mind-reading”
– grasping intentions, goals, desires.
emotional communication
crying
• Crying –communication of emotion
• Response to distress
– Development of emotional self-regulation
• Mastery of environment – agency
• Biofeedback loop
• Soothing
–
–
–
–
–
Swaddling – tight wrapping of baby in cloth
Touch
Sweet taste
Soft, rhythmic sounds
Vibration
crying disorders
• Colic (1 in 10 infants; birth – 12 weeks)
– Extended periods of intense crying
– Cause unknown
• Immature nervous system
• Hyper-sensitivity
• Digestive problems
• Prolonged crying (beyond 12 weeks)
– Exhibit developmental and behavioral disorders
crying disorders
• Prolonged crying expose the brain to high levels of
cortisol, adrenaline, and other damaging chemicals.
–
–
–
–
–
–
Damage to hippocampus
Reduced levels of vasopressin and serotonin
Reduced levels of emotional regulation
Impaired memory
Increased levels of aggression/violence/bullying
Increased levels of anxiety disorders
early emotional expression
• Earliest emotion
– global arousal states of attraction and withdrawal
– set the stage for further development
– develop into well-organized, sustained signals
• Basic emotions
– emotions that can be directly inferred from facial expressions.
• happiness, interest
• surprise, fear, anger
• sadness, disgust
Basic emotions:
A) Universal across all human cultures
B) Present in other advanced species
C) Include guilt, shame, embarrassment
D) A&B
E) All of the above
emotional self-regulation
•
Strategies for adjusting emotional state to a comfortable
(adaptive) level of intensity in order to accomplish goals
•
•
•
•
Infants: withdrawal, distress, crying -- need soothing
4 mos: shift focus of attention
1 year: approach/retreat from stimulus
Parent response to distress is important
•
Sympathetic
– child more easily soothed, more self-regulated
•
Non-responsive (wait to intervene)
– child enters into rapid, intense distress
– harder to soothe
– doesn’t develop self-regulation
emotional self-regulation
• When an infant’s needs are met, they can focus on
the world around them and explore.
– Their brains take in and adapt to stimulation from the
external world.
• When they aren’t met, they become fixated on
trying to get their needs met.
– They stop exploring and shut out other stimulation
from the external world.
emotions of others
• Emotional contagion: babies match the emotional
expressions of caregiver
7-10 mos: infants perceive facial expressions as organized
patterns, can match facial expression to emotion
8-10 mos: social referencing- relying on another person’s
emotional reaction to appraise situation (e.g.- visual cliff)
• Still face experiment
http://www.youtube.com/watch?v=apzXGEbZht0
Mirror neurons help infants experience others’ emotions:
A) Yes, because they help them match emotional facial expressions
B) Yes, because they stimulate a matching internal experience
C) Yes, because they allow infants to empathize with others.
D) A&B
E) No, because mn’s are only involved in imitation of physical behavior
social referencing
• Example of how adults help child regulate emotion
• Permits toddlers to compare their assessments of
situations with others
• Helps young children move beyond simply reacting
to emotional messages
• Visual cliff experiment
http://www.youtube.com/watch?v=eyxMq11xWzM
temperament
• Constitutionally based individual differences in
–
–
–
–
Emotion
Motor function
Attentional reactivity
Self-regulation
• Influences the way that children develop, display,
and control emotions
• Foundation for later personality
temperament styles
• Types
– Easy
– Difficult
– “Slow to warm up”
Which child will be
harder to
reward/punish?
A) Easy child
B) Difficult child
• Differences in sociability
• Differences in punishment/reward
temperament styles
• What else affects the development of
temperament?
• Gender
• Cultural differences
• Goodness of fit (with parents/environment)
cognitive development
theory differences
• Piaget stage theory
• Child as “blank slate” (everything learned)
• Focus on learning as a process within individuals
• Core-knowledge theory
– Child possesses innate knowledge (domains of thought)
• Socio-cultural theory
– Focus on learning as a social process between
individuals
Piaget’s theory
• Constructivist approach – children actively construct
knowledge for themselves in response to their
experiences.
• Child as scientist:
– Generate hypotheses
– Perform experiments
– Draw conclusions
• Children learn many things on their own
– without the help of instruction from adults.
• Children are intrinsically motivated to learn.
• Discontinuous (qualitative) change
– different ages think differently.
conservation of quantity (1)
conservation of quantity (2)
Information processing
• Computational approach – cognitive development as a passive
maturation process that occurs over time.
• Child as a computational system
• Children undergo continuous (quantitative) cognitive change
• Development through increasingly sophisticated hardware and
software
– Faster and more efficient processing, larger memory bank, better
learning “algorithms”
– More content knowledge (learned facts) to draw upon
Core-knowledge theories
• Child as well-adapted product of evolution
• Emphasis on sophistication of children’s thinking in
areas that have had evolutionary importance.
– Eg. environment navigation, face recognition, language
– Naïve physics, psychology, biology
• Some advanced capacities already present (innate)
• Move from “general” to “domain specific” specialized
learning mechanisms
Naïve physics
• Infants have a surprisingly sophisticated understanding of
how the physical world works.
understanding intentions
• They also have a pretty sophisticated understanding of how the
psychological world works
– e.g., they understand that there are goals and intentions and that only
certain creatures can have them.
primitive morality
?
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Chapter 04-06 Infancy - Jen Wright`s Website