Chapter 5: Physical Development in Infants and Toddlers 5.1 Healthy Growth 5.2 The Developing Nervous System 5.3 Motor Development 5.4 Sensory and Perceptual Processes

5.1 Healthy Growth Features of Human Growth Variations on the Average Profile Mechanisms of Physical Growth Challenges to Healthy Growth

Features of Human Growth Follows the cephalocaudal principle Muscles become longer and thicker During the first year, a layer of fat is added Cartilage is replaced by bone 5.1 Healthy Growth

Variations on the Average Profile Secular Growth Trends: generational changes in physical development Average and normal are not the same 5.1 Healthy Growth

Average Height and Weight

Mechanisms of Physical Growth Heredity influences adult height The pituitary gland secretes growth hormone Nutrition is particularly important during infancy when growth is rapid At 2 years, growth slows and kids become “picky” eaters 5.1 Healthy Growth

Challenges to Healthy Growth Malnutrition is especially damaging in infancy Malnutrition needs to be treated with adequate diet and parent training Many diseases that kill young children are preventable with vaccines, improved health care, and changing habits 5.1 Healthy Growth

5.2 The Developing Nervous System Organization of the Mature Brain The Developing Brain

Organization of the Mature Brain Neuron: basic unit of nervous system Cerebral hemispheres: right and left halves of the cortex Frontal cortex: area of the cortex that controls personality and the ability to carry out plans 5.2 The Developing Nervous System

The Neuron

Organization of the Brain

The Developing Brain Brain originates in neural plate Brain regions specialize early (e.g., left hemisphere for verbal functioning; frontal cortex for emotion) “Flexible” brain organization shown by children who recover from brain damage. 5.2 The Developing Nervous System

5.3 Motor Development The Infant’s Reflexes Locomotion Fine-Motor Skills Maturation, Experience, and Motor Skill

The Infant’s Reflexes Newborns’ reflexes prepare them to interact with the world Some reflexes are important to survival (e.g., rooting and sucking) Some protect the newborn (e.g., blink and withdrawal) Some are foundations for later motor behavior 5.3 Motor Development

Locomotion Dynamic Systems Theory: motor development involves many distinct skills Differentiation and integration of component skills (posture and balance, stepping, perceptual skill) is necessary 5.3 Motor Development

Development of Locomotion

Fine-Motor Skills Reaching and grasping becomes more coordinated throughout infancy. Toddlers prefer to use one hand and this preference becomes stronger during the preschool years. 5.3 Motor Development

Maturation, Experience, and Motor Skill Maturation is important: Studies of Hopi infants. Experience matters, too: African infants and training studies 5.3 Motor Development

5.4 Sensory and Perceptual Processes Smell, Taste, and Touch Hearing Seeing Integrating Sensory Information

Smell, Taste, and Touch Even newborns can smell, taste, and feel These skills are useful in recognizing parents and in feeding 5.4 Sensory and Perceptual Processes

Hearing Infants hear well, though not quite as accurately as adults Infants’ hearing is best for sounds that have pitches in the range of human speech Infants use sound to locate objects 5.4 Sensory and Perceptual Processes

Seeing Acuity is 20/400 at birth but improves rapidly Infants perceive colors by 3 or 4 months Infants master perceptual constancies early Many cues are used to infer depth Edges & motion are used to perceive objects 5.4 Sensory and Perceptual Processes

Wavelength of Light

Shape Constancy

Perception of Objects

Use of Motion to Perceive Objects

Infants’ Scanning of Faces

Face-like Stimuli

Integrating Sensory Information By 1 month, can integrate sight and touch By 4 months, can integrate sight and sound 4- and 7-month-olds can match facial appearance (boy or man) with sound of voice 5.4 Sensory and Perceptual Processes

Infant Watching Videos

Time Spent Looking at Videos