Chapter 5 Physical Development in Infancy

Summary

1.0 Images of Life-Span Development: Studying Newborns

Studying newborns is challenging and has prompted researchers to devise various methods to examine their subtle, but complex perceptual motor skills.

2.0 Physical Growth and Development in Infancy

Reflexes. The neonate is not passive. The neonate is born with reflexes and skills necessary to sustain life functions such as sucking, swallowing, and elimination (устранение), and perceptual abilities such as seeing, hearing, and smelling. Other reflexes such as the Moro reflex, grasping, and rooting reflexes are also present. Sucking obtains nourishment, but also can provide researchers with a means to evaluate an infant's attention.

Cephalocaudal and Proximodistal Sequences. Muscular control develops during the first year.
Development follows a cephalocaudal pattern (from the head down) and a proximodistal (периферический) pattern (from the center of the body toward the extremeties).

Height and Weight. The average North American newborn is 20 inches long and weighs 7.5 pounds. Infants grow about 1 inch per month during the first year, and nearly triple their weight by the end of their first year. Rate of growth is slower during the second year of life.

Gross and Fine Motor Skills. Gross motor skills involve large muscle activities whereas fine motor skills entail more precise actions such as finger movements. A milestone in gross motor activity is walking that typical, first occurs at an average of 12-13 months. A milestone in fine motor activity occurs with the development of reaching and grasping skills.

The Brain. Changes in the brain occur during infancy. Although infants probably have all of the neurons their going to have in life by birth, the interconnections between neurons increase dramatically during infancy.

Infant States. Infants show a variety of states of consciousness, including deep sleep, regular sleep, disturbed sleep, drowsy, alert activity. alert and focused attention, and inflexibly focused. Such classification schemes have allowed researchers to determine that the sleep-wake cycle of infants differs from the typical adults. Sudden infant death syndrome (SIDS) is a condition that occurs when an infant stops breathing and suddenly dies without any apparent cause. SIDS is associated with biological vulnerabilities early in development.

Nutrition. Infant’s need to consume about 50 calories per day for each pound of their body weight. A major change during the second half of the first year is the introduction of solid foods. There is a growing consensus that breast­feeding is superior to bottle-feeding, but the increase in working mothers has meant fewer breast-fed babies. A current trend is for working mothers to breast-feed infants in the first several months to build up the infant's immune system, and their bottle-feed after they have returned to work. Marasmus can develop under conditions of severe protein-calorie malnutrition. Malnourished infants are shorter in stature and slower in cognitive growth in middle and late childhood than their better-nourished peers.

Toilet Training. Toilet training entails a motor skill that is expected to be achieved in North American culture by three years of age. The recent trend is toward beginning toilet training later than in the past (e.g., at 20-24 months of age).

3.0 Sensory and Perceptual Development

What Are Sensation and Perception? Sensation occurs when physical energy contacts the sensory receptors whereas perception occurs when our brain interprets what is sensed.

Visual Perception. Visual perception is one of the most-explored areas of infant perception. Robert Fantz used infants gazes to determine that they have visual preferences for patterns over colors or brightnesses. Visual acuity in the neonate is about 20/200, but becomes 20/100 by 6 months of age. Perception of the human face develops over the first five months of life. Depth perception has been demonstrated by using a visual cliff and a natural response in infants of 6 months of age. Infants 2 to 4 months old can discriminate visually between the shallow and deep sides of a visual cliff, but it remains controversial as to whether depth perception is innate.

Hearing. Research on hearing suggests that the ability to hear might exist before birth. Immediately after birth newborns can hear; however, their sensory threshold is higher than that for adults.

Touch and Pain. Newborns clearly respond to touch because many reflexes are easily elicited by mild tactile stimulation. Studies of circumcision indicate that neonates feel pain and that they can cope with it. This finding challenges the medical practice of operating on newborns without providing anesthesia.

Smell. Newborns are sensitive to unpleasant odors such as rotten eggs. Infants 2 to 7 days old can recognize the smell of their mother's milk on a breast pad compared with a breast pad with no milk.

Taste. Sensitivity to taste may be present before birth because increased swallowing has been observed when saccharin was added to the amniotic fluid of a near-term fetus. The facial expressions of newborns differ when they are sucking sweet or sour substances.

Intermodal Perception. Considerable interest focuses on the infant's ability to relate information across perceptual modalities; the coordination and integration of perceptual information across two; modalities— such as the visual and the auditory senses—is called intermodal perception. The direct I perception and constructivist views are two important views of perception that make different j predictions about intermodal perception.

4.0 Contemporary Concerns

Sociocultural Worlds of Development 5.1: Children Living Hungry in America. Many areas in the United States have impoverished families that struggle to put food on the table. Undernutrition is a silent problem in this country.

Perspectives on Parenting and Education 5.1: The Right Stimulation and Suggested Activities for Visual Stimulation. Infants can experience either too little or too much stimulation. Parents should determine the optimal amount and type of stimulation for their child. There are deveiopmentally appropriate activities for the visual stimulation of infants that range from hanging a bright, shiny object within 8-10 inches of the infant's face to showing the infant large pictures in books.

Life-Span Practical Knowledge 5.1: What to Expect in the First Year. This encyclopedic volume presents a broad, developmental milestone approach to infant development during the first year of life.

Life-Span Practical Knowledge 5.2: Solve Your Child's Sleep Problems. Richard Ferber's book is a self-help book for parents who have a child with a sleep disorder. This book helps parents recognize and do something about sleep disorders.

Life-Span Health and Well-Being: Babies Don't Need Exercise Classes. The idea of trying to accelerate an infant's physical skills through an exercise class is unwise; however, there are deveiopmentally appropriate exercise activities and toys for infants.

Key Terms

1.0 Images of Life-Span Development: Studying Newborns

perceptual motor system

2.0 Physical Growth and Development in Infancy

sucking reflex, rooting reflex, Moro reflex,

grasping reflex, nutritive sucking, nonnutritive sucking,

cephalocaudal pattern, proximodistal pattern,

gross motor skills, fine motor skills,

infant states,

sudden infant death syndrome (SIDS),

nutrition,

breast-feeding

bottle-feeding

marasmus

3.0 Sensory and Perceptual Development

sensation, perception, pattern perception,

depth perception, visual stimulation,

auditory stimulation, tactile stimulation,

circumcision

4.0 Intermodal Perception

intermodal perception,

direct perception view,

constructivist view

5.0 Contemporary Concerns

sleep disorder,

undernutrition

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