Chapter 03

CHAPTER 3CHAPTER 3Physical & Cognitive Physical & Cognitive

DevelopmentDevelopmentIn InfancyIn Infancy

Principles of Physical Principles of Physical GrowthGrowth

Cephalocaudal PrincipleCephalocaudal PrincipleGrowth patterns are from the head downGrowth patterns are from the head down

Proximodistal PrincipleProximodistal PrincipleDevelopment proceeds from the center of the body outwardDevelopment proceeds from the center of the body outward

Principle of Hierarchical IntegrationPrinciple of Hierarchical IntegrationSimple skills develop separately & independently but later are Simple skills develop separately & independently but later are integrated into more complex skillsintegrated into more complex skills

Principle of Independence of SystemsPrinciple of Independence of SystemsDifferent body systems grow at different ratesDifferent body systems grow at different rates

Brazelton Assessment Brazelton Assessment ScaleScale

Used to determine Used to determine infants’ neurological & infants’ neurological & behavioral responses to behavioral responses to their environmenttheir environment27 Categories of responses that 27 Categories of responses that measure:measure:

Interactions with othersInteractions with others

Motor behaviorMotor behavior

Physiological controlPhysiological control

Response to stressResponse to stress

The ReflexesThe Reflexes Reflex Stimulation Response Developmental Pattern

Blinking Flash of light, puff Closes both eyes Permanentof air

Babinski Stroke sole of foot Fans out toes, Disappears after 9 months to 1 twists foot year

Grasping Touch palms of hands Grasps tightly Weakens after 3 months,

disappears after 1 yearMoro (Startle) Sudden stimulation Startles, arches back, Disappears after 3 – 4 months

(e.g. loud noise or throws head back, being dropped) flings out arms & legs

then rapidly closesRooting Cheek stroked or Turns head, opens Disappears after 3 – 4 months

side of mouth mouth, begins touched sucking

Sucking Object touches Sucks automatically Disappears after 3 – 4 monthsmouth

Swimming Put face down in Makes swimming Disappears after 6 – 7 monthsin water movements

Stepping Lower feet onto Moves feet as if to Disappears after 3 – 4 monthsflat surface walk

Physical Physical DevelopmentDevelopment

Growth of the Growth of the BodyBodyAverage height & normal height Average height & normal height are not the same thingare not the same thing

Nutrition & Nutrition & GrowthGrowthTypical 2-month-old has 40% of Typical 2-month-old has 40% of body’s energy devoted to growthbody’s energy devoted to growthMust consume large number of Must consume large number of calories relative to body weightcalories relative to body weight Approx. 50 calories per poundApprox. 50 calories per pound Adult needs 15 – 20 calories per Adult needs 15 – 20 calories per poundpound

Developing Nervous Developing Nervous SystemSystem

NeuronDendrites, Cell Body, Axon, Terminal Buttons, Synapse, Neurotransmitters

BrainHemispheres, Corpus Callosum, Frontal Cortex

The Developing Brain & The Developing Brain & Nervous SystemNervous System

The NeuronThe NeuronBasic component of the Nervous Basic component of the Nervous SystemSystem

NumberNumberBetween 100 & 200 Billion at birthBetween 100 & 200 Billion at birth

Growth rate: 250,000 per minuteGrowth rate: 250,000 per minute

Synaptic pruningSynaptic pruning

MyelinMyelinFatty tissue covering the axonFatty tissue covering the axon

Associated with critical periodsAssociated with critical periods

Emerging Brain Structures

Neural Plate Flat structure that develops in the zygote about 3 weeks after conceptionAt 4 weeks it folds to form neural tube that becomes brain & spinal cord MyelinFatty wrap around axon that speeds up neural transmission

Begins at about 4 months Synaptic PruningSynapses begin disappearing Language ProcessingCortex in left hemisphere specializes in language processing early in life, probably by birth

Brain Brain DevelopmentDevelopment

PlasticityPlasticityThe Degree that the brain is modified by experience

Sensitive PeriodSensitive PeriodA time in development when the organism is susceptible to environmental influences in relating to some particular facet of development

Influence on the Influence on the EnvironmentEnvironmentGreater stimulation produces greater growth

Neural Plasticity Extent to Which the Brain is Organized is FlexibleThe brain like office building with rooms designed to be used to meet different needs of the company

Neurons are created and begin migrating throughout cortexBiochemical paths pull them A neuron can end up anywhere There are no specific genetic instructions Brain construction similar in everyone

Experience changes specifics

Rhythms of Rhythms of LivingLiving

Sleep & WakefulnessSleeps 16 – 18 hours per daySleep is in fits & starts

REM SleepBrain waves are different than adultsREM sleep in infants is not associated with dreaming

Sudden Infant Death Syndrome

Disorder where a Disorder where a seemingly healthy seemingly healthy infant dies in its sleepinfant dies in its sleepAffects 1 in 1000 infants in the U.S.Affects 1 in 1000 infants in the U.S.

No apparent causeNo apparent cause

Leading cause of death in children one Leading cause of death in children one yearyear

At risk children: At risk children: Boys, African-Boys, African-American, low-birthweight, low Apgar American, low-birthweight, low Apgar scorers, mothers who smoked, certain scorers, mothers who smoked, certain brain defects, & abused childrenbrain defects, & abused children

All races, socio-economic levels, & All races, socio-economic levels, & those with no health problems victimsthose with no health problems victims

Nutrition & Motor Nutrition & Motor DevelopmentDevelopment

MalnutritionHaving an improper amount & balance of nutrients

Has negative results

Slower growth rate

Lower IQ

Kwashiorkor

Marasmus

ObesityWeight greater than 20% above the average for a given height

Physical Development

Breast Feeding insures proper nourishmentBreast Feeding insures proper nourishmentAdvantages to breast feeding:Advantages to breast feeding: 1. immune advantages from mother’s antibodies1. immune advantages from mother’s antibodies 2. less prone to diarrhea & constipation2. less prone to diarrhea & constipation 3. make transition to solid foods more easily3. make transition to solid foods more easily 4. breast milk can’t be contaminated4. breast milk can’t be contaminated 5. formula-fed infants more prone to allergies5. formula-fed infants more prone to allergies

MalnutritionMalnutrition1 in 3 Children Worldwide Under Age 5 Malnourished1 in 3 Children Worldwide Under Age 5 Malnourished about 20% U.S. children get inadequate iron, & 10% go to bed hungryabout 20% U.S. children get inadequate iron, & 10% go to bed hungry Malnourished develop slower than peersMalnourished develop slower than peers Especially damaging during infancyEspecially damaging during infancy Lower IQ, more easily distracted, shorter attention span, inattentive, Lower IQ, more easily distracted, shorter attention span, inattentive, tire more easilytire more easily

Early Motor Early Motor SkillsSkills

Motor SkillsCoordinated Movements of Muscles & Limbs Locomote: Moving about in the world Fine motor skills: Grasping, holding, & manipulating objects

Locomotion: The Dynamic Systems Theory Motor development involves many distinct skills that are organized & reorganized over time to meet the demands of specific tasks Posture & Balance are fundamental to walking Growth of legs & muscles are important to maintain upright posture

SteppingTransfer of weight from one foot to another Component skills must be mastered

Perceptual Factors Need to judge whether surface is suitable for movement

Coordinating Skills Differentiation: Mastery of component skills Integration: Combining them in the proper sequence into a coherent, working whole Learning to walk demands orchestration of many specific skills

Fine Motor SkillsFine Motor Skills Reaching & Reaching & GraspingGrasping 4 Months Can Reach for Objects requires hand-eye & individual finger coordination 6 Months Coordinates Both Hands 1 Year Can Generally Feed Self

HandednessHandedness90% Worldwide Right Handed Young babies have no preference 13 months handedness Genetics Major Role in Handedness

PerceptionSightEye, optic nerve, occipital area of brain relatively well-developed at birth Visual acuity Smallest pattern that can be distinguished dependably; clarity of vision Newborns respond to light & can track moving objects with the eyes

Color Cones Neurons specialized in the eye for color Perceive few colors Newborns can differentiate blue from gray & red from green, not yellow from green or yellow from red

Depth Visual Cliff At 1 ½ months placing on deep side of cliff heart rate decelerates Deceleration occurs when something interesting occurs Notices difference between sides of cliffRetinal disparity: Difference between left & right eye images Used to judge depth cues Infants use visual cues and sound to judge depth

PerceptionProcess by which the brain receives, selects, modifies, & organizes sensory information Smell & Taste Infants respond positively to pleasant smells Infants have highly developed sense of tasteSweet, sour, salty, bitter, umami

Touch & Pain Nervous system can transmit pain Behavior in response to pain-provoking stimuli suggests they experience pain Hearing Hearing is best in range of human speech By 4½ months can recognize own name Infants can distinguish different pitches

Development Development of the Sensesof the Senses

Visual PerceptionNeonate can see only about 1 footMinutes after birth shows preferences for certain stimuliWithin a few hours prefers mother’s face

Auditory PerceptionAble to hear prior to birthPrefers mother’s voice

Smell & TasteStrong sense of smell & taste

Pain & TouchPainful stimuli produce physical & emotional responses

The Senses in The Senses in GeneralGeneral• An Infant sees only An Infant sees only

about 1 foot but can about 1 foot but can perceive depth.perceive depth.

• It sees shapes and It sees shapes and prefers novel images.prefers novel images.

• It recognizes faces and It recognizes faces and prefers attractive faces prefers attractive faces over those not over those not attractive.attractive.

• An Infant is able to An Infant is able to hear from at least the hear from at least the 66thth month in utero. month in utero.

• It can identify its It can identify its mother’s voice as well mother’s voice as well as its own voice.as its own voice.

• It recognizes the sound It recognizes the sound of another infant/child of another infant/child who is in distress.who is in distress.

Piaget’s Piaget’s TheoriesTheoriesBasic Principles of Cognitive Development

Assimilation: when new experiences are incorporated into existing schemes; e.g. grasping one thing extends to others Accommodation: when schemes are modified based on experience; learns some things are too heavy to lift Equilibration & Stages of Cognitive Development: recognition of schemes to return to a state of balance Assimilation & accommodation usually in balance Schemes sometimes need to be adjusted to new experiences When balance is upset, disequilibrium occurs and there is aneed to change

Information ProcessingInformation Processing

AttentionProcess that determines which sensory information receives additional cognitive processingOrienting response: fixation on a stimulus & changes in heart rate & brain activityHabituation: diminished response to a stimulus as it becomes familiar

LearningClassical conditioning: a neutral stimulus produces a response that was originally produced by another stimulusInfants learn that a stimulus is a signal for what will happen nextInfants form expectations about what will happen in their environmentOperant conditioning: focus is on relation between consequences of behavior & the likelihood the behavior will occurImitation: watching others to see how they behave

Stages of Cognitive Development

Sensorimotor Thinking Sensorymotor Stage: birth – 2 years

Birth - 1 month

Exercises reflexes1 - 4 months

Primary circular reactions: Accidentally produces pleasing event involving body & try to recreate it

4 – 8 months Secondary circular reactions:New actions repeated with objects8 – 12 months intentional behaviors engaged in12 – 18 monthsTertiary circular reactions:Repeats old schemes with new objects trying to understand why different objects give different outcomes 18 – 24 months Symbolic usage crowning achievement of sensorymotor stage

LanguageLanguage

Road to SpeechPerceiving speech:Babies can distinguish speech soundsCan hear the entire range of phonemes in all languagesBy 8th month can recognize sound patterns that are heard repeatedlyCan recognize stressed syllables & sounds in native languageInfant-directed speech (motherese) helps infants perceive the sounds fundamental to their language

Steps to SpeechEarliest sounds:CooingVowel-like sounds (o-o-o-o or a-h-h-h)BabblingSpeechlike sounds that have no meaning (dah or bah)

First WordsFirst Words ++ Language That’s UnderstoodFirst words have a structure borrowed from advanced babblingGenerally consists of vowel pairs repeatedMama or dada

Referential styleVocabularies that are dominated by words that are names of objects, persons, or actions

Expressive styleVocabularies that include some names but also many social phrases used like single words (“Go away,” “What’d you want?” & “I want it”)

First WordsFirst Words ++Fast Mapping of WordsChild’s ability to connect new words to referents so rapidly that he cannot consider all possible meanings for the new wordJoint attentionParents label objects & children rely on adults’ behavior to interpret the words they hear

LabelingRules children use to learn new words with unfamiliar word in the presence of objects already known and some not known, unfamiliar word refers to objects not knownA name refers to the whole object & to all objects of the same typeIf an object already has a name & another name, the new name denotes a subcategory of the original nameGiven many similar category members, a word applied consistently to only one of them is a proper noun