Life Span DevelopmentLife Span DevelopmentSpring 2010Spring 2010Physical Development in Infancy – Chapter 4Cognitive Development in Infancy - Chapter 5

Physical Development in Physical Development in InfancyInfancyPhysical Growth & Development: 4 Principles of Growth: Cephalocaudal Development

◦ Cephalocaudal – derived from Greek and Latin roots meaning “head to tail”

◦ Upper part of the head to the lower parts of the body◦ We develop visual abilities before we learn to walk

Proximodistal Development◦ Proximodistal based on latin words for “near” and “far” ◦ Trunk outward – from body’s central axis toward periphery

(extremities) Principle of Hierarchical Integration

◦ Simple skills develop separately and independently but later are integrated into more complex tasks

Principle of the Independent Systems◦ Different body systems grow at different rates. ◦ Growth in one system does not mean that there is growth in

another area. ◦ Example is in puberty when a young female grows sexual

characteristics such as enlarged breast’s but height does not change much during this time.

Growth and Stability:Growth and Stability:Nervous system and brain growthNervous system and brain growth

Neurons - Basic unit of nervous system; receive and transmit messages◦ Dendrites – receive messages

◦ Axons – transmit messages

◦ Neurotransmitters – chemical messengers

◦ Myelin – insulation of axon; enables efficient rapid transmission of messages

Myelination is part of the maturation process Interconnections among neurons form:

◦ Knowledge◦ Memory◦ Physical abilities◦ Senses

Anatomy of the Neuron

Growth and Stability:Growth and Stability:Nervous system and brain growthNervous system and brain growthAt birth:

◦ Infants are born with between 100 and 200 billion neurons

◦Most neurons have relatively few connections to other neurons

◦As you grow the neurons form new connections.

◦Stronger connections equal more skill at a particular activity.

◦After birth, neurons increase in size◦Pruning Down: Severing of

unnecessary/unused connections.◦Born with many more neurons than

you will need.

Development of Neural Connections

Development of the BrainDevelopment of the BrainBrain: Command center of

developing organism

Structures of the Brain

◦ Medulla: control of vital functions (heartbeat & respiration)

◦ Cerebellum: control of balance and equilibrium

◦ Cerebrum: depth of human learning, thought, memory, and reasoning

Cerebral Cortex: upper layer of the brain (wrinkled surface of the cerebrum)

Structures of the Brain

Growth and Stability:Growth and Stability:Brain LateralizationBrain Lateralization

Brain will begin to become more differentiated and specialized. Certain functions are located more in one hemisphere than the other. Becomes more pronounced during the preschool years.________________________________________________________ Left Hemisphere:

◦ Verbal- Speaking Reading Thinking Reasoning

◦ Processes information sequentially. One piece of information at a time.

Right Hemisphere: ◦ Nonverbal-

Spatial relationships Patterns/Drawing recognition Music Emotional expression

◦ Processes information holistically.

Shaken Baby SyndromeShaken Baby SyndromeAlthough the bones of the skull protect

our brain, we are still susceptible to various types of injury

Shaken baby syndrome is a type of inflicted traumatic brain injury that happens when a baby is violently shaken. 

Infants have weak neck muscles and a large, heavy head. 

Shaking makes the fragile brain bounce back and forth inside the skull and causes bruising, swelling, and bleeding, which can lead to permanent, severe brain damage or death. 

Characteristic injuries of Characteristic injuries of shaken baby syndromeshaken baby syndromeSubdural hemorrhages (bleeding in

the brain)Retinal hemorrhages (bleeding in the

retina)Damage to the spinal cord and neckFractures of the ribs and bones

Shaken baby syndrome often causes irreversible damage.

In the worst cases, children die due to their injuries.

Children who survive may Children who survive may have:have:partial or total blindness hearing loss seizures developmental delays impaired intellect speech and learning difficulties problems with memory and attention severe mental retardation cerebral palsy

Environmental Influences on Environmental Influences on Brain DevelopmentBrain DevelopmentPlasticity – The degree to which a

developing structure or behavior is modifiable due to experience

Restricted vs. Enriched environments:◦ Research with nonhuman animals has revealed

the nature of the brain’s plasticity◦ The results of various studies have supported the

fact that restricting early experiences interferes with normal perceptual and intellectual development

◦ Conversely, exposure to sensory diversity provided by an enriched environment allows animals to build up numerous and more complex neural circuits or networks. These circuits are utilized in new learning.

Sensitive PeriodsSensitive PeriodsDuring early brain development there

are sensitive periods during which particular experiences affect brain maturation.

Although certain experiences are essential for orderly brain development to proceed, the occurrences of some noxious experiences will cause harm to the developing organism.

Sensitive periods suggest that a certain level of stimulation is necessary during a sensitive period to prevent failure to develop certain capabilities

Primary Behavior States Primary Behavior States State - refers to degree of awareness infants display to both internal

and external stimulation. Wakeful states - infants may be:

◦ alert and attentive◦ fussing ◦ crying

Sleep states include: ◦ Quiet sleep (infants’ eyes are closed and respiration is slow and

regular) ◦ Active sleep (infants eyes are closed, but move intermittently,

respiration is uneven, they may smile, frown, suck, sob, sigh etc). Transition states between sleep and wakefulness and between sleep

states. In the months following birth, the active sleep state accounts for

about ½ of infants’ total sleep This gradually declines and by 6 months, only about 1/3. Different states produce different brain wave patterns, which can be

measured by an electroencephalogram (EEG) Newborns have highly irregular brain wave patterns, although they

start to become more regular by approximately 3 months old

Active Sleep vs. REMActive Sleep vs. REMDo infants dream?

◦What would they dream about?◦How would we know?

No know knows the answer, although experts say it is unlikely that they do.

Research has shown that infants’ brain wave patterns during active sleep are qualitatively different from those of adults who are dreaming

SIDS: Sudden Infant Death SIDS: Sudden Infant Death SyndromeSyndromeSIDS is the leading cause of death among

infants 1 month to 1 year old, and claims the lives of about 2,500 each year in the United States.

It remains unpredictable despite years of research.

As the name implies, SIDS is the sudden and unexplained death of an infant who is younger than 1 year old.

It's a frightening prospect because it can strike without warning, usually in seemingly healthy babies.

Most SIDS deaths are associated with sleep (hence the common reference to "crib death") and infants who die of SIDS show no signs of suffering.

More on SIDSMore on SIDSWhile most conditions or diseases usually

are diagnosed by the presence of specific symptoms, most SIDS diagnoses come only after all other possible causes of death have been ruled out through a review of the infant's medical history and environment.

SIDS deaths are distinguishable from those resulting from accidents, abuse, and previously undiagnosed conditions, such as cardiac or metabolic disorders.

When considering which babies could be most at risk, no single risk factor is likely to be sufficient to cause a SIDS death. Rather, several risk factors combined may contribute to cause an at-risk infant to die of SIDS.

Risk factorsRisk factorsMost deaths due to SIDS occur between

2 and 4 months of age potential riskRisk factors include:

◦ smoking, drinking, or drug use during pregnancy

◦ poor prenatal care ◦ prematurity or low birth-weight ◦ mothers younger than 20 ◦ tobacco smoke exposure following birth ◦ overheating from excessive sleepwear and

bedding ◦ stomach sleeping

"Back to Sleep""Back to Sleep" Striking evidence that stomach sleeping might

contribute to the incidence of SIDS led the American Academy of Pediatrics (AAP) to recommend in 1992 that all healthy infants younger than 1 year of age be put to sleep on their backs (also known as the supine position).

Since the AAP's recommendation, the rate of SIDS has dropped by over 50%. Still, SIDS remains the leading cause of death in young infants, so it's important to keep reminding parents about the necessity of back sleeping.

Many parents fear that babies put to sleep on their backs could choke on spit-up or vomit. According to the AAP, however, there is no increased risk of choking for healthy infants who sleep on their backs.

Tips for Reducing the Risk of Tips for Reducing the Risk of SIDSSIDS “back to sleep”

Place your baby on a firm mattress to sleep (never on a couch, waterbed or other soft surface)

Alone in crib to prevent rebreathing (No pillow, blankets, comforters, stuffed toys)

Prevent overheating. Research suggests that a baby who gets too warm could go into a deeper sleep, making it more difficult to awaken.

Do not smoke, drink, or use drugs while pregnant and do not expose your baby to secondhand smoke.

Receive early and regular prenatal care. Make sure your baby has regular well-baby checkups. Breastfeed, if possible. If your baby has GERD, be sure to follow your doctor's

guidelines on feeding and sleep positions. Put your baby to sleep with a pacifier during the first year of

life. While infants can be brought into a parent's bed for nursing or

comforting, parents should return them to their cribs or bassinets when they're ready to sleep. It's a good idea to keep the cribs and bassinets in the room where parents' sleep. This has been linked with a lower risk of SIDS.

Motor Development in Motor Development in InfancyInfancyReflexes – unlearned, organized,

involuntary responses that occur automatically in the presence of certain stimuli.

Most infant reflexes have survival value, or evolved because they had survival value at some point in history.

Some reflexes remain throughout the lifespan, others disappear.

Reflexes serve as good diagnostic tools for pediatricians because they appear and disappear according to a timetable.

ReflexesReflexes◦Rooting reflex◦Swimming reflex◦Eye-blink reflex◦Moro reflex◦Startle reflex◦Sucking reflex◦Stepping reflex◦Babinski reflex

Landmarks of Physical Landmarks of Physical Achievement: Gross and Fine Achievement: Gross and Fine Motor SkillsMotor SkillsFine Motor Skills

◦Skills involving small muscles used in manipulation

Development of Hand Control

◦At birth: grasping is reflexive

◦3 months: grasping becomes voluntary Ulnar Grasp: 4 fingers and palm

◦9 to 12 months Pincer grasp: use of oppositional thumb

Locomotion: Use of Gross Motor Locomotion: Use of Gross Motor SkillsSkillsLocomotion

◦ Movement from one place to another

◦ Requires gross motor skills

Skills using large muscles involved in locomotion

Predictable sequence of activities◦ Roll over − Crawl − Walk

◦ Sit up − Stand − Run

Timing of milestones varies among infants◦ Normal “range” versus exact age

Motor Development Milestones in Locomotion

Developmental DiversityDevelopmental DiversityTiming discussed as far as achieving

milestones are based on norms – the average performance of a large sample of children of a given age.

All children meet milestones at different times and they will achieve them when they are ready.

Many factors come into play, including readiness and practice (e.g. baby who gets a lot of “tummy time” will likely roll over sooner than infant who is rarely put on their belly to play).

The appearance of specific motor skills is in part determined by cultural factors.

Sensation and Perception

Sensation: stimulation of sensory organs & transmission to brain

Perception: organization of sensations

I. Development of Vision

Visual Acuity and Peripheral Vision

◦ Neonates are nearsighted and have poor peripheral vision

◦ Visual acuity improves at 6 months are reaches adult levels by 3 – 5 yrs.

◦ Peripheral vision reaches adult levels by 6 months

Visual Preference

◦ At 2 months, show preference for human faces (especially attractive)

◦ By 3 – 5 months: differentiated reactions to emotional faces

Depth Perception

◦ Respond to depth cues by 6 – 8 months (coincides with crawling)

Development of the Senses

The Visual Cliff

Development of the SensesII. Auditory PerceptionThe ability to hear begins

prenatallyInfants can differentiate changes in

melodies and sounds (skill required to learn language)

Can differentiate their mother’s voice from others

Infants are more sensitive than adults to high and low frequencies, but not to the middle ranges

Development of the SensesIII. Smell and TasteInfants react to unpleasant

smells and tastes from birthNewborns can detect their

mother’s scent (if breastfed)Infants have an innate sweet

tooth (they will suck harder on a bottle with milk that is sweetened)

Development of the SensesIV. Sensitivity to Pain and TouchInfants are born with the capacity

to feel painSome of the basic reflexes

require tough (e.g. rooting)Children gain information

regarding the world around them by touching (e.g. babies 6 months old put everything in their mouth)

Cognitive DevelopmentCognitive DevelopmentCognitive Development

◦ Development of children’s ways of perceiving & mentally representing the world.

Schemes◦ Mental structure involved in the acquisition

and organization of knowledge.◦ Assimilation: Incorporation of new events

into existing schemes. People understand an experience in terms of their current way of thinking.

◦ Accommodation: Modification of schemes to incorporate new knowledge. People change their existing ways of thinking when they encounter new stimuli or events.

Jean Piaget’s Approach to Jean Piaget’s Approach to Cognitive DevelopmentCognitive Development

Cognitive development is an orderly sequence of stages.

Focus is on the change in understanding that occurs as a child moves through each stage.

◦Four stages of cognitive development Sensorimotor Preoperational Concrete operational Formal operational

Sensorimotor Stage ( 0 to 2 years)

◦ Developments demonstrated by sensory and motor activity.

◦ Infants progress from responding to reflexes to goal oriented behavior.

Mental representations and problem solving

6 Stages of Sensorimotor Development

Stage 1: Simple Reflexes (0 – 1 mo)

◦ Assimilation of new objects into reflexive responses.

◦ Accommodation can serve to modify inborn reflexes through experience.

Stage 2: Primary Circular Reactions (1 – 4 mo)

◦ Coordination of certain sensory and motor schemes.

◦ Repeat stimuli that first occurred by chance.

◦ The focus is on infants own body.

◦ Goal directed behavior begins to emerge

Transition from “look and see” to “look in order to see”

The Sensorimotor Stage

Stage 3: Secondary Circular Reactions (4 – 8 mo)

◦ Repeated actions meant to bring about a desirable consequence on the outside world.

◦ Infant begins to act on the world (“rattles” or shakes a rattle).

◦ Shift in focus and initial cognitive awareness of external world. Stage 4: Coordination of Secondary Schemes (8 – 12 mo)

◦ Coordination of secondary schemes to achieve certain goals.

◦ Emergence of mental representations – object permanence develops

◦ Object Permanence: Recognition that objects continue to exist even when they are not

seen. First six months

Out of sight, out of mind By 8 – 12 months

Will begin to look for objects that have been hidden.

◦ Gain ability to imitate actions of others

The Sensorimotor Stage

Stage 5: Tertiary Circular Reactions (12 – 18 mo)

◦ Purposeful adaptations of established schemes to specific situations.

◦ Overt trial and error in problem solving.

◦ Experimental quality to behavior (child conducting “miniature experiments”.

Stage 6: New Means Through Mental Combinations (18 – 24 mo)

◦ The capacity for mental representation, or symbolic thought. A mental representation is an internal image of a past event or

object.

◦ Mental trial and error in problem solving.

◦ Child gains the ability to pretend and to imitate someone who is not currently present

Development of Object Permanence

Analysis of PiagetAnalysis of PiagetSupport: Most developmentalists agree with Piaget’s

description of cognitive development during infancy

Research has supported his theory that children learn about the world around them by acting on objects in their environment

Criticisms: Some developmentalists have questioned the

stage concept, instead suggesting that development is more continuous

Piaget’s work is grounded in motor development, ignoring sensory and perceptual abilities

Recent research has suggested that object permanence and imitation may occur earlier than Piaget reported

Information Processing◦ How children take in, use and store information◦ Development is dependent on memory◦ Three basic aspects of memory: encoding, storage and retrieval

Encoding – the process by which information is initially recorded in a form usable to memory

Storage – placement of material into memory Retrieval – the process by which information is located and brought into

awareness◦ Infantile amnesia – the lack of memory for experiences that occurred prior

to 3 years of age Intelligence

◦ Individual differences in cognitive development can be measured.◦ Bayley Scales of Infant Development (evaluates infants development from

2-42 months) Mental Scale Motor Scale Behavioral Rating Scale

◦ Measurement of infant’s intelligence is difficult and unreliable – association between most measures of infancy and adult intelligence is minimal.

◦ Can detect sensory and neurological problems and handicaps.

Information Processing / Intelligence

Bayley Scales of Infant Development

AgeAge Mental ItemsMental Items Motor ItemsMotor Items

1 month1 month Infant quiets when lifted.Infant quiets when lifted. Infant makes postural Infant makes postural adjustment when lifted.adjustment when lifted.

2 months2 months Infant glances between two Infant glances between two objects over crib.objects over crib.

Infant hold head steady Infant hold head steady when carried.when carried.

5 months5 months Infant transfers object Infant transfers object between hands.between hands.

Infants attempts to pick up Infants attempts to pick up object out of reach.object out of reach.

8 months8 months Development of object Development of object permanence.permanence.

Infant raises him/herself into Infant raises him/herself into sitting position.sitting position.

12 months12 months Infant imitates words that Infant imitates words that are spoken.are spoken.

When requested, infants When requested, infants stands up.stands up.

14 – 16 months14 – 16 months Infant builds tower with two Infant builds tower with two blocks.blocks.

Infant walks alone with Infant walks alone with good coordination.good coordination.

The Roots of LanguageThe Roots of LanguageLanguage is the systematic, meaningful

arrangement of symbols which provides the basis for communication

Language includes several formal characteristics:◦ Phonology – the basic sounds of language

(phonemes) that can be combined to form words or sentences. Ex: “a” in “mat” and “mate” are two different

phonemes English language - 40 phonemes to make up the

entire language◦ Morphemes – the smallest language unit that

has meaning. “s” for plural or “-ed” for past tense

◦ Semantics – rules that govern the meaning of words and sentences.

Language Development in Infancy

◦ Infants display prelinguistic communication through sounds, facial expressions, gestures and other nonlinguistic means

Early Vocalizations

◦ Pre-linguistic vocalizations (babbling)

◦ Babbling – making speech-like, but meaningless sounds

◦ Starts at 2-3 months of age and continues until about 1 year

◦ Even deaf children “babble” – infants exposed to sign language will “babble” with their hands (vocal babbling and hand “babbling” activate similar areas of the brain – Broca’s Area)

Development of Vocabulary

◦ Receptive vocabulary grows faster than expressive vocabulary.

Understand many more words than they can produce

◦ First words are generally spoken between 10-14 months of age

◦ First words are typically holophrases, one-word utterances that stand for an entire phrase

“ma” might mean “Where’s Mommy”, “get me out of my crib Mommy” or “Mommy, give me back the remote!!”

Language Development

By 15 months of age, the average child has a vocabulary of 15 words

Overextension◦ Using words too broadly, generalizing their meaning◦ Ex: “doggie” for dogs, cats, rabbits, squirrels, etc (anything with

fur and four legs) Underextension

◦ Using words too restrictively◦ “blankie” describes baby’s blanket, but refuses to call other

blankets “blankies” Telegraphic Speech

◦ First sentences are typically one word utterances◦ Brief expressions that have the meaning of sentences◦ Two-three word sentences (18 to 24 months)

Words not critical to meaning of sentence are left out “I showed you the book” is shortened to “I show book”

Show understanding of syntax “Mommy go” and “Go Mommy” have different meanings.

Language Development