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8. Physical Development in Early Childhood . Read Berk Chapter 8 Physical Growth Brain growth, lateralization Motor Development Gross motor skills Fine motor - drawing Problems – injuries Pre-school books: Assignment 2 early cognition & discussion. Growth in Early Childhood.
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8. Physical Development in Early Childhood Read Berk Chapter 8 • Physical Growth • Brain growth, lateralization • Motor Development • Gross motor skills • Fine motor - drawing • Problems – injuries • Pre-school books: Assignment 2 • early cognition & discussion Class 8, 1 November, 2006
Growth in Early Childhood • Each year from age 2 to 6: • Well-nourished children gain 3” & 4 ½ lbs /yr • By age 6: • average wt = 46 lbs (21Kg), • average ht = 46” (117cm) • Size depends on: genes, health, nutrition • Are asynchronies in growth • Body systems differ in the timing of their maturation Class 8, 1 November, 2006
Growth in Early Childhood Class 8, 1 November, 2006
Growth in Early Childhood Factors influencing growth: • Heredity & hormones • Emotional well-being • Sleep • Nutrition Class 8, 1 November, 2006
Factors influencing growth Heredity & hormones: • Genes influence when hormones are released • Two hormones released - pituitary gland • growth hormone (GH) - height • thyroid stimulating hormone • Stimulates thyroid to release thyroxin • Nerve cells of brain, influences GH Class 8, 1 November, 2006
Factors influencing growth • Emotional well-being (lack of) • Extreme emotional deprivation interferes • With release of GH • Can lead to psychosocial dwarfism • Very short stature • decreased GH secretion • Immature bone growth • Serious adjustment problems • Is reversible • if emotionally inadequate environment removed Class 8, 1 November, 2006
Factors influencing growth Sleep: • GH is released during sleep • Well-rested child better able to play, learn • Deep sleep ~ physical growth & repair • 2-3 yr olds need 12 – 13 hrs sleep • 4-6 yr olds need 10 - 11 hrs sleep • Usually stop napping between age 3 & 4 yr Class 8, 1 November, 2006
Helping young children sleep • 2-yr olds in conflict with parents • Want to be independent • Want a sense of control (Erikson) • Autonomy vs shame & doubt • Initiative vs guilt • But can’t do a lot of what they want to • Want to do things that exceed their abilities or limits set by parents • Get frustrated • Need structure, routine, help to help them cope Class 8, 1 November, 2006
Helping young children sleep • Based on what you know about young children’s needs & their issues with conflict & control… • What can adults (parents) do • or what conditions can be set up to help young children get good sleeps? Class 8, 1 November, 2006
Helping Young Children Sleep • bed time Class 8, 1 November, 2006
Factors influencing growth Nutrition • Appetites decrease between age 2 – 6 yr • Makes parents fret, threaten, cajole • Is not usually medical problem unless no gain • Major problem is lack of iron, zinc, calcium • Too few fruits & veggies, too much fat! • No more than 30% of diet from fat • ~ 1500 – 1700 cal /day for early childhood • Rigid likes & dislikes ~ age 2 – 4 yrs • Strong preferences decline after age 3 Class 8, 1 November, 2006
Factors influencing growth Nutrition: http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/res/fg_preschoolers-prescolaire_ga_e.html#2 at Health Canada Typical servings for preschooler: Canada Food Guide • Grains: (5-12 /day) • ½ - 1 slice bread; 1/4 –1/2 bagel, bun, pita, cup of pasta, rice • Veggies, fruit: (5-10 /day) • ½ - 1 fruit; 1/4 -1/2 cup juice, veggies • Milk: (2-3 /day) • 1 – 1 ½ oz cheese, ½ cup yogurt, 2 cups milk /day • Meat, alternatives: (2-3 /day) • 1–1½ oz meat, 1 egg, 1-2 tblsp peanut butter, ¼ - ½ cup beans Class 8, 1 November, 2006
How to introduce new foods What ways can parents & caregivers help preschoolers accept wider selection of foods? • Strategies • Psychological-emotional approach Class 8, 1 November, 2006
How to introduce new foods Help preschoolers accept wider selection foods by: (Health Canada, 2005) • Presenting food in appealing ways. • combine colours, textures, shapes of food; • Encouraging familiarity with different foods • offer small quantities of new food beside familiar one • Regularly introduce new foods • Let them help grow, buy, prepare, & serve food • Respecting individual food preferences. • Every child has different likes & dislikes. • Offer and encourage, but don’t force Class 8, 1 November, 2006
Brain Development Between ages 2 & 6 yrs: • brain goes from 70% - 90% of adult weight • Continues to undergo dynamic changes • Well into young adulthood • Grey matter for focal thinking within an area • White matter for connections between areas Class 8, 1 November, 2006
Study of Brain Development 3 magnetic resonance methods: Casey et al., 2005 • Structural mri: • anatomical views, structural architecture • Diffusion tensor imaging (DTI): newest • Is an index of brain connectivity • Analyses diffusion of water in white matter • tracts myelinated fibres - regularity & orientation • Functional mri (fmri): • Measures changes in blood oxygen in brain • Assumed to reflect neural activity Class 8, 1 November, 2006
Structural/Functional • Structural Image: whole brain 10-15 mins • Functional Images: whole brain 2 – 10 secs Class 8, 1 November, 2006
Brain Development Brain maturation processes: Both regressive & progressive processes occur: • Synaptic pruning of grey matter • Number of synapses reduced if unused • More elaboratation of stimulated neurons • Myelination of white matter • Increasing connectedness among brain regions Class 8, 1 November, 2006
Brain Development Myelination • Process - nerves become insulated with myelin • But not essential for basic communication. • Sensorimotor, visual, auditory cortex earliest • Corpus callosum myelinates rapidly • Prefrontal cortex myelinates last Class 8, 1 November, 2006
Brain Development All of brain maturation processes - • Follow a sequence • parallels cognitive milestones in development • First sensorimotor areas mature, • Then temporal & parietal association areas • Then higher-order association areas – prefrontal Class 8, 1 November, 2006
Developmental trends in brain maturation Reds-Yellow=gray Purple-Blue=white Class 8, 1 November, 2006
Brain Development Prefrontal cortex • Executive area – planning & analyzing • Working Memory • Ability to inhibit impulsive behaviours • Self-control, self-regulation • Myelination starts ages 3 – 6 years • Maturation not complete until adolescence Class 8, 1 November, 2006
Prefrontal cortex Immature prefrontal cortex: • Impulsiveness & perseveration in young children • Eg typical 3-yr old will jump from task to task • Unable to sit still for long, • Put puzzle together many times, sing same song, hear same story, • Tantrum as uncontrollable emotional perseveration • Normal for a 2-yr old to have a tantrum, not a 10-yr old • development of emotional control reflects both Class 8, 1 November, 2006
Brain Development Lateralization of function develops • Specialization or dominance of functions • Left hemisphere • controls right side of body for motor activities • dedicated to logic, analysis, language, sequences • Myelination of Wernicke’s area is first • language understanding • Then Broca’s area • language production • Thought to control positive emotions Class 8, 1 November, 2006
Brain Development Class 8, 1 November, 2006
Brain Development Lateralization develops • Right hemisphere • controls left side of body for motor processes • Integrator, holistic, big picture, creative impulses • Important for understanding emotional tone – • language & non-verbal signals • Thought to process negative emotions • Although dominance is based on 1 hemisphere, • all cognitive & motor functions use both sides of brain Class 8, 1 November, 2006
Brain Development Handedness • Preference (& proficiency) for using one hand for skilled motor activities • Develops by age 5 • 90% are right handed, 10% left-handed Class 8, 1 November, 2006
Brain Development Language lateralization • Left hemisphere dominant for language • in 96% of right handers; 4% bilateral • 76% of left-handers; 14% bilateral; 10% right • Females less lateralized than males • Language asymmetry develops after age 4 • If brain injury occurs: • before age 3, language shifts to other hemisphere • from age 4-8, language shifts within same hemisphere. Class 8, 1 November, 2006
Brain Development Brain maturation processes in early childhood: • Can sit in one place for an hour • Scan a page of print, move eyes systematically • For complex motor control: • catch ball, then throw, • skip, kick a ball • tie shoe laces, • balance and control in riding a bike Class 8, 1 November, 2006
Brain Development Brain maturation processes: • Allow child to think, react quicker than toddler • Listen & think before talking or acting • Eg, Listen, keep all facts in mind, then respond • Scan picture to focus on one thing • Remember facts & set of instructions • Pivotal when several thoughts occur rapid sequence • Control their emotions Class 8, 1 November, 2006
Motor Skill Development in Early Childhood • Gross Motor Skills • Walking, running • Catching, throwing, swinging, riding • Fine Motor Skills • Dressing, eating • Drawing Class 8, 1 November, 2006
Motor Development From 2 – 6 yrs • Preschoolers make huge strides in gross-motor skills & fine motor skills • Eg hopping, skipping, riding a bike, draw • What do these skills require? • balance, coordination, quick switches Class 8, 1 November, 2006
Gross Motor Skills Principles of development of motor skills • Number of body parts involved • increases lead to greater force • Range of motion involved • Increases lead to greater force • Length of limb at contact • Full extension, greater force Class 8, 1 November, 2006
Development Gross Motor Skills • Developmental sequence catching a ball: • 1. No reaction • Ball bounces off chest, arms rigid waiting • reactions too slow, maybe fear (eyes close, cringe, turn head away) • 2. Traps ball • Contact with arms, not hands, elbows flex to trap ball • 3. Attempts to catch ball with hands • Slight flexion in arms & body but timing is poor – misses often • 4. Mature catch • Body & arms relaxed, ready to absorb force, move in any direction • Hands held in different positions ~ where ball is Class 8, 1 November, 2006
Development Gross Motor Skills • Developmental sequence throwing a ball: • 1. Arm action only • No step, no body rotation • 2. Formative • Homolateral step, no body rotation • 3. Mature • Contralateral step, body rotation, & longer backswing Class 8, 1 November, 2006
Motor Development • What factors are involved in development of motor skills? • Myelination & sculpting of brain, • maturation of prefrontal cortex, • growth of muscles, • change in body size, proportion • slimmer fingers Class 8, 1 November, 2006
Enhancing Early Childhood Motor Development • Mastered through play with peers • Formal lessons have little impact • Daily routines support motor abilities • Provide appropriate play space and equipment • Promote fun and positive attitude Class 8, 1 November, 2006
Fine Motor Control • 2-yr-olds - difficulty with fine motor skills • pouring juice, cutting food with fork & knife, drawing with control, tying a bow • Have trouble with complex skills • two hands • Need motor control, patience, judgment • practice • Why? • Short, stubby fingers • neurological immaturity Class 8, 1 November, 2006
Fine Motor Control • Pre-schoolers do become more dextrous • Develop better control of small muscles • ability to make precise, delicate hand & finger movements • Same time as better gross-motor skills Class 8, 1 November, 2006
Fine Motor Control • Can begin to care for themselves • Dressing • zippers first (2-3), then buttons (3-4) • Most 5-yr olds can dress & undress themselves • Tying shoes – mastered at age 6. • Most complex skill requiring attention, memory, dexterity • Can draw pictures • Gradually > skilled at holding crayons/markers Class 8, 1 November, 2006
The importance of drawing • Purpose for children: • sensory exploration • express thoughts/feelings • reflect knowledge of world • What drawing reveals about children: • motor co-ordination • self-concepts • emotions • social attitudes Class 8, 1 November, 2006
Development of Drawing 3 stages: • Scribbles (12 months +) • First shapes & forms that represent things • ~ 2 yrs: realize that pictures depict objects • 2 - 3 yrs: impose meaning on picture • 3 - 4 yrs: use lines to represent boundaries Class 8, 1 November, 2006
Development of Drawing • More realistic drawings • Age 5 - 6 yrs: more complex; plan picture • start to coordinate actions & thoughts • take care with colour, • stand back to see results • Age 6 - 7 yrs: more realism • eg, 3D drawings Class 8, 1 November, 2006
Early Drawings 3 yr 2 mo 3 yr 7 mo 4 yr 4 yr 2 mo 5 yr 1 mo From Seifert & Hoffnung 11 yr 13 yr Class 8, 1 November, 2006
Early Drawings Human Figure Drawing • a. ‘TADPOLES’ • b. circle for head, • no body, • pair of vertical lines for legs • c. child adds 2nd circle for body • another pair of lines for arms From Cole & Cole Class 8, 1 November, 2006
Early Drawing Children’s maps(Piaget & Inhelder, 1948/1956) • Drawings of familiar neighbourhoods: • Preschoolers (3 - 4 yrs) • landmarks are fragmented and disorganised • Early school (5 - 6 yrs): • landmarks organised around familiar routes of travel • but not mastered relationship of one route to another • Middle childhood (6+ yrs): • better overall picture of larger scale space Class 8, 1 November, 2006
Childhood Injuries • Preschoolers eager to explore • But lack cognitive skills to know when they are in danger. • Neurological immaturity means young children impulsive, unable to think things through Class 8, 1 November, 2006
Childhood Injuries • Unintentional injuries are leading cause of childhood mortality • Most common injuries: • Traffic accidents, drowning, burns, falls, poison • Canadian rate: 9.7 deaths/100 000 age 1 -14 • is almost twice Swedish rate (5.2) • and much higher than UK rate (6.1) Class 8, 1 November, 2006
Childhood Injuries • Traffic accidents account for: 41% of deaths, • then drowning 15% • for every injury-related death there are 40 hospitalizations and ~ 670 emergency room visits to treat injuries(Health Canada, 1999) Class 8, 1 November, 2006
Childhood Injuries • Having an ‘accident’ implies a random, unpredictable, uncontrollable event • No one is to blame • Injury & injury control imply harm can be minimized & maybe prevented • Three levels of injury prevention: • Primary prevention • Secondary prevention • Tertiary prevention Class 8, 1 November, 2006