Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Chapter 2: Infancy Module 2.1 Physical Development in Infancy

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. GROWTH AND STABILITY

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Physical Growth Rapid growth during first two years 87

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. An Interesting Head Count

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Nervous System and Brain Nervous system comprises the brain and the nerves that extend throughout the body Neurons are the basic cells of the nervous system 87

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Quick Check Neurons Dendrites Axons Neurotransmitters Synapses 87

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Brain Physiology Structure and function – Forebrain – Cerebral cortex has four lobes Two hemispheres usually work together and each lobe has a primary function Frontal, occipital, temporal, parietal lobes – Amygdala – Hippocampus The Brain

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The Brain Fig. 3.7 The Brain’s Four Lobes

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Functions of Lobes of the Cortex Frontal lobes Occipital lobes Temporal lobes Involved in voluntary movement, thinking, personality, and intentionality or purpose Function in vision Active role in hearing, language processing, and memory Parietal lobes Roles in registering spatial location, attention, and motor control The Brain

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Development of the Brain By age 6, almost adult size. Brain growth spurts: coincide with changes in cognitive behavior Cerebellum, largest part of brain, divides into halves Lateralization, specialties of each hemisphere; left: language and logical thinking; right: visual and spatial functions

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Brain Physiology Neurons — nerve cells handling information processing at the cellular level – Axon, dendrites, synapses – Neurotransmitters: dopamine – Myelin sheath and myelination – Neural circuits Lateralization — specialization of functions in one hemisphere of cerebral cortex The Brain

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The Neuron The Brain Fig. 3.8

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The Brain In Infancy Shaken Baby Syndrome Extensive brain development in utero – Born with about 100 billion neurons – Enriched early experiences can enhance brain growth and functioning – Brain flexibility and resilience demonstrated in deprived environments Experience determines brain connections –Enriched and deprived environments The Brain

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The Brain In Infancy Changing neurons – Myelination; visual and auditory – Rapid growth of myelin sheath, dendrite and synapse connections – Blooming and pruning of connections in brain – Peak synaptic overproduction influenced by heredity and environment The Brain

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The Brain In Infancy At birth, greater activity in left hemisphere specializes as infants listen to speech Motor control begins about 2 months Brain areas do not mature uniformly; skills affected by myelination and interconnections The Brain

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Major Systems of the Brain Brain stem Limbic system Cerebral cortex

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. How great brains grow! Birth: – billion neurons –Relatively few neurons-neuron connections During first two years: –Billions of new connections established and become more complex 88

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Use it or lose it! Synaptic pruning Unused neurons are eliminated Allows established neurons to build more elaborate communication networks with other neurons Development of nervous system proceeds most effectively through loss of cells Myelin 88

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Form and Function: Brain Growth Neurons reposition themselves with growth, becoming arranged by function –Cerebral cortex –Subcortical levels 89

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Don’t shake the baby! Shaken Baby Syndrome –Brain sensitive to form forms of injury –Shaking can lead to brain rotation within skull Blood vessels tear  severe medical problems, long-term disabilities, and sometimes death 89

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Environmental Influences on Brain Development Plasticity Sensitive period 89

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Critical Period: specific time when a given event (or absence) has specific impact on development. Not absolutely fixed. Plasticity: ability to modify Sensitive Periods: especially responsive to specific type of experience

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Without feedback from the environment (that is, without experience) how can further development occur? A child raised in a deprived environment with inadequate stimulation and feedback might fail to learn. The damage to a child is significant when love and attention are absent.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Critical & Sensitive Periods Critical and sensitive periods are both times when the organism is biologically primed to most benefit from a particular experience. Sensitive Periods: adverse effects caused by missing a sensitive period may be overcome at a later time, although with great difficulty.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Critical Periods: adverse effects caused by missing a critical period are permanent. The only clearly demonstrated critical period in human beings involves early stimulation of certain neural and body cells. Without such stimulation, these cells atrophy and die (e.g., visual neurons must have light during their early development or they will die. Depth perception may occur as well.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The first 5 to 6 years of childhood may be a critical period for the development of the brain. Even when a part of the brain is damaged, if damage occurs before age 5/6, the brain may compensate and take over the functions. After age six, highly unlikely.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Other ways a child may suffer permanent disability by early childhood: 1.occurrence of irreparable physical damage upon which later development will depend 2.a critical period that passes without the child’s obtaining the necessary experience or stimulation 3.a situation where the child is kept by their culture or environment from ever obtaining the learning necessary for proper development.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Do Baby Einstein programs really work?

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. What do babies do all day? Life Cycles of Infancy Wake Sleep Eat Defecate 89

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Rhythms and States State –One of major body rhythms –Degree of awareness infant displays to both internal and external stimulation –Change in state alters amount of stimulation required to get infant’s attention 90

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Sleep: Perchance to Dream Major state –16-17 hours daily (average); wide variations Different than adult sleep –2 hour spurts; periods of wakefulness –Cyclic pattern By 16 weeks sleep about 6 continuous hours; by 1 year sleep through night (See table 2-2) 90-91

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. REM Sleep Period of active sleep Closed eyes begin to move in a back-and-forth pattern Takes up around one-half of infant sleep May provide means for brain to stimulate itself through autostimulation 91

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. SIDS Sudden infant death syndrome Leading cause of death in children under 1 year of age Back-to-sleep guidelines (AAP) Differential risk –Boys –African American infants –Low birthweight –Low APGAR scores –Mother’s smoking –Some brain defects –Child abuse 92

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. SIDS is found in children of every race and socioeconomic group and in children who have had no apparent health problems Back-to-sleep is important! 92

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply REVIEW The major principles of growth are the cephalocaudal principle, the proximodistal principle, the principle of hierarchical integration, and the principle of the independence of systems. The development of the nervous system first entails the development of billions of neurons and interconnections among them. Later, the numbers of both neurons and connections decrease as a result of the infant’s experiences. 93

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply REVIEW Babies integrate their individual behaviors by developing rhythms—repetitive, cyclical patterns of behavior. 93

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply APPLY What evolutionary advantage could there be for infants to be born with more nerve cells than they actually need or use? How might our understanding of synaptic “pruning” affect the way we treat infants? 93

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. MOTOR DEVELOPMENT

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Reflexes: Inborn Physical Skills Reflexes: learned, organized involuntary responses that occur automatically in presence of certain stimuli 93

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. What did you see? Take two minutes to list the reflexes you saw in the clip.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Why do reflexes come and go?

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Ethnic and Cultural Differences and Similarities in Reflexes Reflexes –Genetically determined –Universal Cultural variations in ways displayed –Moro reflex Serves –Diagnostic tool –Social function –Survival function 94

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Motor Development in Infancy Milestones of Normal Motor Development 96

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Motor Development in Infancy Fine Motor Skills 96

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Developmental Norms Comparing Individual to Group Norms: –Represent the average performance of a large sample of children of a given age. –Permit comparisons between a particular child’s performance on a particular behavior and the average performance of the children in the norm sample. –Must be interpreted with caution. Brazelton Neonatal Behavior Assessment Scale (NBAS) 96

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Nutrition in Infancy Fueling Motor Development Without proper nutrition, infants cannot reach physical potential and may suffer cognitive and social consequences Infants differ in growth rates, body composition, metabolism, and activity levels 98

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. So what is a healthy caloric allotment for infants? About 50 calories per day for each pound of weight Most infants regulate their caloric intake quite effectively on their own If are allowed consume as much they seem to want, and not pressured to eat more, they will be healthy 98

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Malnutrition Children living in many developing countries Slower growth rate Chronically malnourished during infancy = later lower IQ score 98

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Are problems of malnourishment restricted to developing countries?

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. When Malnutrition Is Severe Maramus Kwashiorkor 98

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Nonorganic Failure to Thrive Sufficient nutrition Symptoms Reversal 99

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. “A fat baby is a healthy baby”? 99

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Is Breast Best?

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Introducing Solid Foods: When and What? Solids can be started at 6 months but are not needed until 9 to 12 months (AAFP) –Introduced gradually, one at a time –Cereal  strained fruits 100

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply 101 REVIEW Reflexes are universal, genetically acquired physical behaviors. During infancy children reach a series of milestones in their physical development on a fairly consistent schedule, with some individual and cultural variations.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply REVIEW 101 Nutrition strongly affects physical development. The advantages of breast-feeding are numerous.

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply 101 APPLY What advice might you give a friend who is concerned that her infant is still not walking at 14 months, when every other baby she knows started walking by the first birthday?

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Learning the World Sensation Perception 101

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Visual Perception: Seeing the World Newborn’s distance vision ranges from 20/200 to 20/600 By 6 months, average infant’s vision is already 20/20 Other visual abilities grow rapidly –Binocular vision –Depth perception 102

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Infant Visual Preference Preferences that are present from birth –Genetically preprogrammed to prefer particular kinds of stimuli –Prefer to look at patterned over simpler stimuli 102

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Auditory Perception: The World of Sound Infants –Hear before birth and have good auditory perception after they are born –Are more sensitive to certain frequencies –Reach adult accuracy in sound localization by age 1 –Can discriminate groups of different sounds –React to changes in musical key and rhythm –Can discriminate many language related sounds 103

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Smell and Taste in a Small World Smell –Well developed at birth –Helps in recognition of mother early in life Taste –Have innate sweet tooth –Show facial disgust at bitter taste –Develop preferences based on what mother ate during pregnancy 103

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. The Power of Touch Touch is one of most highly developed sensory systems in a newborn Even youngest infants respond to gentle touches Several of the basic reflexes present at birth require touch sensitivity to operate 104

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Becoming an Informed Consumer of Development Exercising Your Infant’s Body and Senses Attempts to accelerate physical and sensory- perceptual development yield little success »Yet Infants need sufficient physical and sensory stimulation 105

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. How can this be accomplished? Carry a baby in different ways Let infants explore their environment Engage in “rough-and-tumble” play Let babies touch their food and even play with it Provide toys that stimulate the senses, particularly toys that can stimulate more than one sense at a time 105

Discovering the Lifespan - Robert S. Feldman Copyright © 2009 Pearson Education, Inc., Upper Saddle River, NJ All rights reserved. Review and Apply REVIEW Infants’ sensory abilities are surprisingly well developed at or shortly after birth. Their perceptions help them explore and begin to make sense of the world. Very early, infants can see depth and motion, distinguish colors and patterns, localize and discriminate sounds, and recognize the sound and smell of their mothers. Infants are sensitive to pain and touch, and most medical authorities now subscribe to procedures, including anesthesia, that minimize infants’ pain. 106