Intro Activity: Handout 8-4 Developmental Landmarks: Physical, Cognitive, Language, Social

• 1-Laugh-2 months• Pedal a tricycle-24 months• Sit without support-5-6 months• Feel asahmed-2 years• Walk unassisted-12 months• Stand on 1 foot for 10 seconds-4 ½ years• Recognize and smile at mother or father-4-5 months• Kick Ball forward-20 months• Think about things that cannot be seen-2 years• Make two-word sentences-20-22 months

• Did you overestimate? underestimate?

Motor Milestones

Developmental Psychology

• Cross-sectional: uses participants of different ages to compare how variables change over lifespan – Advantage: immediate comparison of developmental differences – Disadvantage: cannot tell if an individual stays the same or changes over time.

• Longitudinal: same group of individuals studies repeatedly over time. – Advantage: allows the study of developmental patterns or changes over time. – Disadvantage: time; must wait many years for results, subjects "drop out" of

study (death, move, etc.) – Preferred method

Issue Details

Nature/NurtureHow do genetic inheritance (our nature) and experience (the nurture we receive) influence

our behavior?

Continuity/Stages Is development a gradual, continuous process or a sequence of separate stages?

Stability/ChangeDo our early personality traits persist through life, or do we become different persons as we

age.

Prenatal Development• Prenatal: germinal, embryonic, fetal stages

– Germinal: first two weeks after conception• Zygote – a fertilized egg

– Embryonic: weeks three through eight after conception• Stage when most miscarriages occur & when most major birth defects take place • Placenta & umbilical cord

– Connects blood supply of mother to the fetus – Filter: allows oxygen & nutrients thru while keeping out some toxic substances– But: some viruses (HIV) & drugs (caffeine, nicotine, pot, cocaine, heroin) can

get through, which are called TERATOGENS » diseases (herpes) » drug (alcohol)—FAS » other environmental agent (chemicals)

– Fetal: two months after conception until birth• Neurological development

– Neural connections are very few at birth, but # in the 1,000s by 2 months – Partial explanation for brain weight increase from 340-900 grams

Newborn: Sensory Abilities• All are present at birth; vision is the one that changes the most • Hearing

– Prefer mother’s voice to other female’s voices, but do not prefer fathers voice to other males

• exposure during gestation • Touch

– Many reflexes are triggered by touch, and sensitivity increases as neonates mature

• rooting (turn head toward touch/stroke) • sucking • moro (the "startle" reflex= drawing up limbs when startled, or "dropped")• withdrawal (from painful stimuli) • grasping ("palmar") • babinski (spread toes when feet are stimulated/stroked) • sphincter (pooping)

– Touch creates emotional bonds between people • Taste

• Neonates prefer liquid solutions such as sugar and milk and grimace when given bitter or salty tastes. inborn preference for sweet & salt; inborn dislike for bitter

Prenatal Development

• While most nerve cells are produced during the first few months of prenatal development, the senses cannot work until these cells make synapses. Early reflexes and movements seem to function in making these connections, molding the senses, and training the fetal brain to perceive.

• Chronological summary of sensory development:1. Nerve growth begins when a sheet of cells on the back of the embryo folds in the middle to form the future

spinal cord. At one end, the tube enlarges to form the brain’s major sections.2. First responses are reflexes, some of which occur even before the sense of touch is developed. The fetus will flex

its head away from stimulation around the mouth as early as 71⁄2 weeks. By month’s end the ears begin to take shape.

3. Touch receptors around the mouth are developed by the twelfth week and elsewhere by the fifteenth. Touching the palms makes the fingers close, touching the soles of the feet makes the toes curl down, touching the eyelids makes the eye muscles clench. Nerve cells have multiplied, synapses are being formed.

4. At 15 weeks the fetus can grasp, frown, squint, and grimace. It may suck its thumb and swallow. These movements correspond to the development of synapses in the brain.

5. At 20 weeks nerve-cell production slows as the existing cells grow larger and make more complex connections. The senses of taste and smell are now formed. The nerve cells serving each of the senses are developing into specialized areas of the brain.

6. The fetus can feel movement and may respond to sound as early as 24 weeks.7. At 25 weeks some babies born prematurely can survive. Nerve supply to the ears is complete. Brain scans show

response to touch at 26 weeks and to light at 27 weeks. A light shone on the mother’s abdomen will make the fetus turn its head, indicating some functioning of the optic nerve.

8. The eyes open in the womb and the fetus may see its hand and environment. Some researchers put the start of awareness at the 32nd week, at which time neural circuits are as advanced as a newborn’s. Brain scans show periods of deep sleep.

9. The fetus begins to develop daily activity cycles. At 35 weeks hearing is mature. At birth the baby can see shapes and colors within 13 inches of its face; can distinguish loudness, pitch, and tone; and may even show a preference for sweets and for the scent of its mother’s skin.

Newborn: Sensory Abilities• Vision

– Infants are born with immature visual system• can detect movement and large objects

– At four months visual acuity is the same as an adult 20/20 – Response to complex stimuli and the human face

• 8-12 weeks: Neonates prefer stripes to featureless blobs, and curvy lines to straight ones

• 2 months: Neonates prefer human faces – Depth perception

• 6-8 months: respond to monocular and binocular cues • Gibson "visual cliff" experiment (6-8 months)

– Crawling infants would not cross visual cliff even when beckoned by mother – 1-month old infants showed no emotion in response to a visual cliff, 55-day

old infants showed interest, and 9-month olds showed fear

Newborn: Sensory Abilities• Smell

– 1 day old can differentiate citrus/floral odors – Can discriminate distinct smells shortly after birth – Infants breathe more rapidly when presented with a strong smell 16

hours to 5 days after birth, and will turn away from fowl smells – Infants prefer similar smells to children and adults – Infants are drawn to the smell of their mother – Auxiliary: underarm

• Within 15 days infants prefer their mother’s auxiliary odors to those of other women

Developmental Norms

• Development Norms - average age at which individuals display various behaviors and abilities. – Variations from average are normal. EX: 25% of all babies walk by 11 months, 50% walk within a week after

their first birthday, and 90% by age 15 months• 30 percent rule – developing motor skills more than 30% later than average might warrant attention.

– Occurs in a predictable sequence• Proximodistal principle: parts closer to the center of the body develop before parts further away.

– EX: activities involving the trunk are mastered first (roll over before walking or holding a bottle)• Cephalocaudal principle: parts of the body closer to the head develop before parts closer to the feet.

– EX: head lifts before roll over, sit up before (controls legs to) crawl – Most heavily influenced by maturation

• Biological growth processes that enable orderly developmental changes that are RELATIVELY uninfluenced by experience.

– Development of the brain pathways fire up nerve endings and muscle groups to perform specific tasks

– For example, can’t roll over until three brain structures develop more: the motor cortex, which initiates movement and the cerebellum, which excites motor nerves and regulates balance.

• However, the timing can be sped up/slowed down by experience/learning (nurture) – A child that is always held by their parents will be slower to learn how to crawl

– Each stage has critical periods - the period before humans must be exposed to a skill/experience or they lose much of their innate ability to learn it

• EX: have to be exposed to language before puberty in order to learn language)– Development is lifelong and NEVER ends – it is plastic, flexible and malleable

Maturation

At birth 3 months 15 monthsCortical Neurons

Cognitive Development• Cognition = all the mental activities associated with thinking,

knowing, remembering, and communicating• Methods for studying infants:

– Infant reflexes provide insight into their mental life• Gaze = preference looking and duration related to visual

perception• Head turning = related to auditory attention• Sucking , reaching, kicking can be used to measure

interest– Habituation = decreasing responsiveness with

repeated stimulation– Dishabituation = increasing responsiveness to

something new or impossible• http://www.learner.org/vod/vod_window.html?pid=1502 (8 minutes – 20

minutes)

Piaget’s Stages of Cognitive Development• Schema--mental structure or framework that permits

classification/organization of new information. • Assimilation--inclusion of new event into existing schema. • Accommodation--modification of schemas to allow for new

information can be integrated.

Piaget’s Stages of Cognitive Development: Sensorimotor Stage

Age Range

Major Developmental Hallmarks

0-2 yrs 3 ½ mos 6-8 mos

- All knowledge is acquired through senses and movement (such as looking and grasping). - Baby Mathematics – infants stare longer at a numerically impossible event

- Visual Cliff – infant hesitates and shows fear; depth perception - Object Permanence - exhibit memory for things no longer seen.

Cognitive Development• Baby Mathematics

– Shown a numerically impossible outcome, infants stare longer (http://vsx.onstreammedia.com/vsx/pbssaf/search/PBSPlayer?assetId=68933&ccstart=0&pt=0&preview= (5:39)

1. Objects placedin case.

2. Screen comesup.

3. Object is removed.4. Impossible outcome:Screen drops, revealing two objects.

4. Possible outcome:Screen drops, revealingone object.

Cognitive Development• One study had 1 month

old babies suck one of two pacifiers without ever seeing them

• When shown both pacifiers, infants stared more at the one they had felt in their mouth

• This requires a sort of reasoning

Piaget’s Stages of Cognitive Development: Preoperational Stage

Age Range

Major Developmental Hallmarks

2-7 yrs3 yrs 4-5yrs

- Language development- Symbolic Thinking - ability to think in symbols - Animism – all objects have thoughts and feelings. - Egocentric Thinking – unable to see world from others’ points of view (your thoughts are public knowledge rather than private, everyone thinks like you). - Theory of Mind – start to understand people’s ideas about their own and others’ mental states (feelings, perceptions, and thoughts and the behavior these might predict)

Theory of Mind

http://vsx.onstreammedia.com/vsx/pbssaf/search/PBSPlayer?assetId=68935&ccstart=0&pt=0&preview= (start at 2:55 or at 7 minutes for sticker game)

Autism & Theory of Mind: Video: “Breaking the Shell”

Developmental Abnormalities: Autismhttp://vsx.onstreammedia.com/vsx/pbssaf/search/PBSPlayer?assetId=68299&ccstart=925659&pt=0&vid=pbssaf1205&entire=No

Cognitive Deficit Brain Abnormality

Lack Theory of Mind (see others as separate beings with own feelings, thoughts, perceptions):-Social Relationship Difficulties (hard to relate to people)-No eye contact when communicating-No imitation

Dysfunction of mirror neurons – subset of motor neurons that also fire when person watches another person perform the same action (helps one determine intentions of others by mentally stimulating their actions) Brain does not light up to faces

Problems with emotional reciprocity and trivial act can set off an extreme emotional response

Larger Amygdala

Heightened emotional response-Preoccupation with trivial info (train schedules)-Avoids novel sensations-Repetitive motions – rocking, self stimulating (head banging)-Hypersensitivity-Aversion to sounds

Salience landscape – created by amygdala – map that details emotional significance of everything in environment, helps determine how we should respond emotionally

Language Deficits – cannot interpret proverbs and metaphors

Larger Brain?

Treatments for Autism

• Intervene early with autistic children to stimulate brain systems

• Squeeze vest device to monitor arousal• Intensive therapy – 40 hours a week: speech

pathologist, imitation, repetitive actions, provide routine

• Correct chemical imbalance that disables mirror neurons; teach how to suppress Mu wave

Piaget’s Stages of Cognitive Development: Concrete Operations Stage

Age Range

Major Developmental Hallmarks

7-11/12 yrs

- Logical thinking develops, including classifying objects and mathematical principles, but only as they apply to real, concrete objects. - Conservation of liquid, area, volume- Seriation – mentally arrange items along a dimension (height, weight, time or speed)- Classification – sort objects into groups, class inclusion

Conservation Number: In conservation of number tests, two equivalent rows of coins are

placed side by side and the child says that there is the same number in each row. Then one row is spread apart and the child is again asked if there is the same number in each.

Length: In conservation of length tests, two same-length sticks are placed side by side and the child says that they are the same length. Then one is moved and the child is again asked if they are the same length.

Substance: In conservation of substance tests, two identical amounts of clay are rolled into similar-appearing balls and the child says that they both have the same amount of clay. Then one ball is rolled out and the child is again asked if they have the same amount.

Piaget’s Stages of Cognitive Development: Formal Operations Stage

Age Range

Major Developmental Hallmarks

11/12 yrs + up

- Logical thinking extends to hypothetical and abstract concepts. - Can reason using metaphors and analogies- Can explore values, beliefs, philosophies- Can think about past and future- Potential for mature moral reasoning.

Maturation

• Cognitive development is a process of maturation = developmental changes that are genetically or biologically programmed rather than acquired through learning or life experiences. – Object Permanence hippocampus – Theory of mind mirror neuron network– Proliferation of neurons within the frontal lobe moral

reasoning; hypothetical thinking• Due to maturation, the four stages of cognitive

development always occur in the same sequence and at approximately the same ages

Criticisms of Piaget

• Development is seen as more continuous without any particular sequence built into the process rather than discrete stages

• Cognitive abilities result from modeling and learning rather than maturation.

• Age ranges are incorrect – some 3 months old have object permanence.

• Studied his own children - biased and not big enough sample

David Elkind: Adolescent Egocentrism• A heightened self-consciousness of adolescents. Thinking becomes very

introspective and teens often go through periods of extreme self-absorption. Can lead to cognitive limitations:– Imaginary Audience = belief that everyone is watching and the tendency to

overestimate the degree to which one’s behavior will lead to social acceptance or social rejection

• EX: Wrapped up with appearance – everyone will notice pimple, new hair do, etc

• EX: Drink alcohol at party because he/she believes his/her friends will think less of him/her for not drinking

– Personal Fable = perceptions of one’s own uniqueness (experiences, perspectives, feelings, values) and that one is destined for greatness

• EX: “No one has been in love like this before!”; “You don’t understand… you have never had this much work to accomplish in one night!”

• EX: Write in journals about their future as the next great novelist or rock star– Invincibility Fable = belief that one is invincible and can never be hurt.

Regardless of what happens to others, believe no harm will come to them• EX: drinking and driving ; won’t get pregnant, etc…

Vygotsky’s Sociocultural Perspective

• Vygotsky - children learn to think through guided participation in social experiences that explore the world. Adult instruction and encouragement are crucial to the child’s intellectual growth– Zone of proximal development - a range of skills that the child

can perform with assistance but not quite independently• mastering important skills is partly linked to the willingness of others

to provide scaffolding, or sensitive structuring of children’s learning encounters.

– Words are part of the scaffold – words bridge the child’s current understanding and what is almost understood

• What children can do with the help of others may be more indicative of their mental development than what they can do alone

– Critical thinking based on dialogue with others who challenge ideas. Believed language to be the foundation for social interaction and thought